<FULL LOG> below. Rufus version: x.y.z - I have NOT removed any part of it. Additionally (if applicable):
(✓) button to compute the MD5, SHA1 and SHA256 checksums, which are therefore present in the log I copied. I confirmed, by performing an internet search, that these values match the ones from the official image.ISO to USB pass without any error's.
Boot on different PC also work to grub boot loader,
but live OS live starting or install search for cd/dvd.

Used image:
http://mirror.turnkeylinux.org/turnkeylinux/images/iso/turnkey-core-15.0-stretch-amd64.iso
http://mirror.turnkeylinux.org/turnkeylinux/images/iso/turnkey-core-15.0-stretch-amd64.iso.hash
It is same situation with all images of TurnKey Linux
http://mirror.turnkeylinux.org/turnkeylinux/images/iso/
They are Debian based
Rufus version: 3.1.1320
Windows version: Windows 10 64-bit (Build 17134)
Syslinux versions: 4.07/2013-07-25, 6.03/2014-10-06
Grub versions: 0.4.6a, 2.02
System locale ID: 0x0402
Will use default UI locale 0x0402
SetLGP: Successfully set NoDriveTypeAutorun policy to 0x0000009E
Localization set to 'bg-BG'
NOTE: The Bulgarian (Български) translation requires an update, but the current translator hasn't submitted one. Because of this, some messages will only be displayed in English.
If you think you can help update this translation, please e-mail the author of this application
Found USB 2.0 device 'General USB Flash Disk USB Device' (090C:1000)
1 device found
Disk type: Removable, Disk size: 4GB, Sector size: 512 bytes
Cylinders: 487, Tracks per cylinder: 255, Sectors per track: 63
Partition type: MBR, NB Partitions: 1
Disk ID: 0x01595834
Drive has a DOS/NT/95A (F2) Master Boot Record
Partition 1:
Type: FAT32 (0x0b)
Size: 3.7 GB (4009721856 bytes)
Start Sector: 64, Boot: Yes
Found USB 2.0 device 'General USB Flash Disk USB Device' (090C:1000)
1 device found
Disk type: Removable, Disk size: 4GB, Sector size: 512 bytes
Cylinders: 487, Tracks per cylinder: 255, Sectors per track: 63
Partition type: MBR, NB Partitions: 1
Disk ID: 0x01595834
Drive has a DOS/NT/95A (F2) Master Boot Record
Partition 1:
Type: FAT32 (0x0b)
Size: 3.7 GB (4009721856 bytes)
Start Sector: 64, Boot: Yes
Found USB 2.0 device 'General USB Flash Disk USB Device' (090C:1000)
1 device found
Disk type: Removable, Disk size: 4GB, Sector size: 512 bytes
Cylinders: 487, Tracks per cylinder: 255, Sectors per track: 63
Partition type: MBR, NB Partitions: 1
Disk ID: 0x01595834
Drive has a DOS/NT/95A (F2) Master Boot Record
Partition 1:
Type: FAT32 (0x0b)
Size: 3.7 GB (4009721856 bytes)
Start Sector: 64, Boot: Yes
Found USB 2.0 device 'General USB Flash Disk USB Device' (090C:1000)
1 device found
Disk type: Removable, Disk size: 4GB, Sector size: 512 bytes
Cylinders: 487, Tracks per cylinder: 255, Sectors per track: 63
Partition type: MBR, NB Partitions: 1
Disk ID: 0x01595834
Drive has a DOS/NT/95A (F2) Master Boot Record
Partition 1:
Type: FAT32 (0x0b)
Size: 3.7 GB (4009721856 bytes)
Start Sector: 64, Boot: Yes
Found USB 2.0 device 'General USB Flash Disk USB Device' (090C:1000)
1 device found
Disk type: Removable, Disk size: 4GB, Sector size: 512 bytes
Cylinders: 487, Tracks per cylinder: 255, Sectors per track: 63
Partition type: MBR, NB Partitions: 1
Disk ID: 0x01595834
Drive has a DOS/NT/95A (F2) Master Boot Record
Partition 1:
Type: FAT32 (0x0b)
Size: 3.7 GB (4009721856 bytes)
Start Sector: 64, Boot: Yes
Found USB 2.0 device 'General USB Flash Disk USB Device' (090C:1000)
1 device found
Disk type: Removable, Disk size: 4GB, Sector size: 512 bytes
Cylinders: 487, Tracks per cylinder: 255, Sectors per track: 63
Partition type: MBR, NB Partitions: 1
Disk ID: 0x01595834
Drive has a DOS/NT/95A (F2) Master Boot Record
Partition 1:
Type: FAT32 (0x0b)
Size: 3.7 GB (4009721856 bytes)
Start Sector: 64, Boot: Yes
Found USB 2.0 device 'General USB Flash Disk USB Device' (090C:1000)
1 device found
Disk type: Removable, Disk size: 4GB, Sector size: 512 bytes
Cylinders: 487, Tracks per cylinder: 255, Sectors per track: 63
Partition type: MBR, NB Partitions: 1
Disk ID: 0x01595834
Drive has a DOS/NT/95A (F2) Master Boot Record
Partition 1:
Type: FAT32 (0x0b)
Size: 3.7 GB (4009721856 bytes)
Start Sector: 64, Boot: Yes
Found USB 2.0 device 'General USB Flash Disk USB Device' (090C:1000)
1 device found
Disk type: Removable, Disk size: 4GB, Sector size: 512 bytes
Cylinders: 487, Tracks per cylinder: 255, Sectors per track: 63
Partition type: MBR, NB Partitions: 1
Disk ID: 0x01595834
Drive has a DOS/NT/95A (F2) Master Boot Record
Partition 1:
Type: FAT32 (0x0b)
Size: 3.7 GB (4009721856 bytes)
Start Sector: 64, Boot: Yes
Found USB 2.0 device 'General USB Flash Disk USB Device' (090C:1000)
1 device found
Disk type: Removable, Disk size: 4GB, Sector size: 512 bytes
Cylinders: 487, Tracks per cylinder: 255, Sectors per track: 63
Partition type: MBR, NB Partitions: 1
Disk ID: 0x01595834
Drive has a DOS/NT/95A (F2) Master Boot Record
Partition 1:
Type: FAT32 (0x0b)
Size: 3.7 GB (4009721856 bytes)
Start Sector: 64, Boot: Yes
Found USB 2.0 device 'General USB Flash Disk USB Device' (090C:1000)
1 device found
Disk type: Removable, Disk size: 4GB, Sector size: 512 bytes
Cylinders: 487, Tracks per cylinder: 255, Sectors per track: 63
Partition type: MBR, NB Partitions: 1
Disk ID: 0x01595834
Drive has a DOS/NT/95A (F2) Master Boot Record
Partition 1:
Type: FAT32 (0x0b)
Size: 3.7 GB (4009721856 bytes)
Start Sector: 64, Boot: Yes
Found USB 2.0 device 'General USB Flash Disk USB Device' (090C:1000)
1 device found
Disk type: Removable, Disk size: 4GB, Sector size: 512 bytes
Cylinders: 487, Tracks per cylinder: 255, Sectors per track: 63
Partition type: MBR, NB Partitions: 1
Disk ID: 0x01595834
Drive has a DOS/NT/95A (F2) Master Boot Record
Partition 1:
Type: FAT32 (0x0b)
Size: 3.7 GB (4009721856 bytes)
Start Sector: 64, Boot: Yes
Scanning image...
ISO analysis:
Image is an ISO9660 image
Will use '/isolinux/isolinux.cfg' for Syslinux
Detected Syslinux version: 6.03/20171018 (from '/isolinux/isolinux.bin')
Disk image analysis:
Image has an unknown Master Boot Record
Image is a bootable disk image
ISO label: 'core'
Size: 251.4 MB (Projected)
Note: File on disk is larger than reported ISO size by 228 KB...
Uses: Syslinux/Isolinux v6.03
Using image: turnkey-core-15.0-stretch-amd64.iso (252 MB)
Computing checksum for 'D:\DROP\turnkey-core-15.0-stretch-amd64.iso'...
MD5: 3c8eede77e68367dd622895e4ed9f883
SHA1: 66207f2ecfc3cfeeeb6ff562d620be4330b7261c
SHA256: 7c2d654313e934df8a03772680c34cbbc03d93ec6a208961e5f0b85b1c2f68f1
Downloading 'ldlinux.sys' from https://rufus.ie/files/syslinux-6.03/20171018/ldlinux.sys
Unable to access file: 404
Extended version was not found, trying main version...
Downloading 'ldlinux.sys' from https://rufus.ie/files/syslinux-6.03/ldlinux.sys
File length: 68599 bytes
Successfully downloaded 'ldlinux.sys'
Downloading 'ldlinux.bss' from https://rufus.ie/files/syslinux-6.03/20171018/ldlinux.bss
Unable to access file: 404
Extended version was not found, trying main version...
Downloading 'ldlinux.bss' from https://rufus.ie/files/syslinux-6.03/ldlinux.bss
File length: 512 bytes
Successfully downloaded 'ldlinux.bss'
Format operation started
Requesting disk access...
Opened \\.\PHYSICALDRIVE1 for exclusive write access
Requesting lock...
Will use 'G:' as volume mountpoint
I/O boundary checks disabled
Requesting lock...
Analyzing existing boot records...
Drive has a DOS/NT/95A (F2) Master Boot Record
Volume has an unknown Partition Boot Record
Clearing MBR/PBR/GPT structures...
Erasing 64 sectors
Deleting partitions...
Partitioning (MBR)...
Closing existing volume...
Waiting for logical drive to reappear...
Formatting (FAT32)...
Using cluster size: 4096 bytes
Quick format was selected
Creating file system...
Format completed.
Writing master boot record...
Drive has a Zeroed Master Boot Record
Partition is already FAT32 LBA...
Set bootable USB partition as 0x80
Using Syslinux MBR
Found volume GUID \\?\Volume{f87f68fd-a2dc-11e8-9c24-f46d0427b715}\
Installing Syslinux 6.03...
Opened \\?\Volume{f87f68fd-a2dc-11e8-9c24-f46d0427b715} for shared write access
Using existing './rufus_files/syslinux-6.03/20171018/ldlinux.sys' ✓
Using existing './rufus_files/syslinux-6.03/20171018/ldlinux.bss' ✓
Successfully wrote 'ldlinux.sys'
Successfully wrote Syslinux boot record
Successfully remounted \\?\Volume{f87f68fd-a2dc-11e8-9c24-f46d0427b715}\ on G:
Copying ISO files...
Extracting files...
Image is an ISO9660 image
This image will be extracted using Joliet extensions (if present)
Extracting: G:\casper\10root.squashfs (228.4 MB)
Extracting: G:\casper\initrd.gz (18.4 MB)
Extracting: G:\casper\vmlinuz (4 MB)
Extracting: G:\isolinux\boot.cat (2 KB)
Extracting: G:\isolinux\bootlogo (189.5 KB)
Extracting: G:\isolinux\chain.c32 (24.3 KB)
Extracting: G:\isolinux\gfxboot.c32 (10.3 KB)
Extracting: G:\isolinux\isolinux.bin (40 KB)
Extracting: G:\isolinux\isolinux.cfg (109 bytes)
Extracting: G:\isolinux\ldlinux.c32 (113.8 KB)
Extracting: G:\isolinux\libcom32.c32 (177.7 KB)
Extracting: G:\isolinux\menu.cfg (376 bytes)
Extracting: G:\isolinux\vesamenu.c32 (26.1 KB)
Created: G:\syslinux.cfg
Finalizing, please wait...
Created: G:autorun.inf
Created: G:autorun.ico
Found USB 2.0 device 'General USB Flash Disk USB Device' (090C:1000)
Using autorun.inf label for drive G: 'core'
1 device found
Disk type: Removable, Disk size: 4GB, Sector size: 512 bytes
Cylinders: 487, Tracks per cylinder: 255, Sectors per track: 63
Partition type: MBR, NB Partitions: 1
Disk ID: 0x14DC14DA
Drive has a Syslinux Master Boot Record
Partition 1:
Type: FAT32 LBA (0x0c)
Size: 3.7 GB (4008706048 bytes)
Start Sector: 2048, Boot: Yes
Congratulations - By forcing me to edit your report because you still couldn't follow what the checklist asked you to do (is putting crosses into boxes or copy/pasting text, as you were explicitly asked to do, that hard?), you have have earned a __deferred__ tag, meaning that I am going to treat this issue as __super low__ priority and probably won't look into it for a few weeks.
I report bug.
I not need to know BB code and tricks of github posting.
what is difference to write:
I do all steps
vs
all this text and checks
Even and in FAQ there is a мisspellings
mother tongue
From when muscles in the mouth = a vocal and written description of the words used by a nation?
Or in school kids learn French tongue not French language (except in cooking class)
It is too easy to add criticism, but match harder to explain why.
I not need to know BB code and tricks of github posting.
No you don't. But I do expect you to follow text that says:
You MUST read and complete the checklist below, by placing an x into each [ ] (so that it shows '[x]', NOT '[ x]' or '[x ]')
I'm explicitly telling you what I expect you to do, with an example.
If you first __choose__ to ignore it altogether, and then, when opening a new issue precisely after I called you upon it, __choose__ not to follow it, and also __choose__ not to copy/paste the log data as requested, I can only assume that helping you __is__ going to be troublesome because you are not following what you are explicitly being told to do. Therefore, I'm going to be a lot less willing to help you as a matter of priority. People who demonstrate that they can follow the rules always get prioritized over people who don't.
Even and in FAQ there is a мisspellings
I'm sure there are. But I don't see how that relates to your complaint. I am not reducing the priority of your issue because English is not your mother tongue, but because, __twice__, you have demonstrated an unwillingness to even try to follow the rules, and there's only so much credit I can give to the idea that this was by accident.
From when muscles in the mouth = a vocal and written description of the words used by a nation?
There again, a simple googling of _mother tongue_ would have demonstrated that the argument you are trying to make, unfortunately, has no weight. I don't decide on the idioms that are being used by the English language (which, by the way, is not my mother tongue either). But if I were to try to dispute one of them, as you seem to be trying to do, I hope I'd do just a little bit of research to ensure that the argument I am trying to make doesn't fall flat.
It is too easy to add criticism, but match harder to explain why.
I've explained why. Even if English is not your native language, I expect you to be able to follow the instructions with clear examples that I provide when opening an issue. From experience, the fact that you failed to do that, __twice__, means that I'm better off assigning a low priority to your issue.
Creativity vs Bureaucracy = Evolution
Or lets do right job not to chat unneeded.
p.s.
it is not important how to say something, it is important other side to understand it.
I prefer short informative version
You prefer long Political version (99% air under pressure) nothing personal
You prefer log Political version
No. I prefer people who can follow the rules. It's really as simple as that and the root of all this "unneeded chat". The rules are precisely designed so that I don't have to waste more time than I need to fetching files off pastebin or wherever or not being able to see at one glance whether a step was completed or not.
You may think this is just wind, but maybe one day, once you have had to support __thousands__ of people through either an issue tracker or e-mail, you will understand why filtering issues according to who is willing to respect your requests, and who thinks they can just be ignored, is vital to being able to perform your job in the best conditions.
After some testing, it appears that, like other maintainers before them, the Turnkey Linux maintainers seem to have chosen to deviate from what Debian and Ubuntu do, where they make sure they __don't restrict themselves to supporting the ISO-9660 file system only__, and dropped the ability for their __custom__ init script to look for data on FAT32 and other file systems, with the expected result that their script fail.
This is __NOT__ something Rufus can fix, as the issue is due to the distro maintainers being a bit too short-sighted with regards to the file system they support, and needing to modify their media detection script.
__HOWEVER__, once again I have to advise users to stop ignoring that big message that Rufus makes sure to display when it detects that an ISOHybrid is being used (which is the case here), and which is __REALLY THERE TO HELP YOU__ in case the image doesn't boot properly in ISO mode. This is the message that says:

As the dialog __explicitly__ advises (in 38 different languages if it turns out that English is not your mother tongue):
if you encounter issues during boot, you can try writing this image again in DD Image mode.
As it turns out, if you do just that, the image will boot without issues.
So, to summarize:
As such, since there is really nothing for me to address in Rufus, I will close this issue.
This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue if you think you have a related problem or query.
Most helpful comment
After some testing, it appears that, like other maintainers before them, the Turnkey Linux maintainers seem to have chosen to deviate from what Debian and Ubuntu do, where they make sure they __don't restrict themselves to supporting the ISO-9660 file system only__, and dropped the ability for their __custom__ init script to look for data on FAT32 and other file systems, with the expected result that their script fail.
This is __NOT__ something Rufus can fix, as the issue is due to the distro maintainers being a bit too short-sighted with regards to the file system they support, and needing to modify their media detection script.
__HOWEVER__, once again I have to advise users to stop ignoring that big message that Rufus makes sure to display when it detects that an ISOHybrid is being used (which is the case here), and which is __REALLY THERE TO HELP YOU__ in case the image doesn't boot properly in ISO mode. This is the message that says:
As the dialog __explicitly__ advises (in 38 different languages if it turns out that English is not your mother tongue):
As it turns out, if you do just that, the image will boot without issues.
So, to summarize:
As such, since there is really nothing for me to address in Rufus, I will close this issue.