Undecimus: Error: RootFS already mounted: BuildVersions don't match 12.1.2 vs. 12.1.4

[TheChatty]

No OTA file, fresh reboot, but always the same error:

[*] Snapshots on newly mounted RootFS:
[*]     com.apple.os.update-F1CFF5A4FAF7AD63D0BBBA9092C348CB4A5208CC5F23D1F864B61816C0045AE06775A1AE92E93DC6CFB522E327FB52FD
[*]     com.apple.os.update-MSUPrepareUpdate
[*] snapshot VersionPlist: {
    BuildID = "4B4F80DA-FEAD-11E8-8758-EE1D232787AC";
    ProductBuildVersion = 16C101;
    ProductCopyright = "1983-2018 Apple Inc.";
    ProductName = "iPhone OS";
    <ProductVersion = "12.1.2";
    SystemImageID = "D94F0DBF-0332-4A74-BB55-907D39D22030";
}
[*] rootfs VersionPlist: {
    BuildID = "523EBB10-28F9-11E9-ABB4-920B8C797186";
    ProductBuildVersion = 16D57;
    ProductCopyright = "1983-2019 Apple Inc.";
    ProductName = "iPhone OS";
    ProductVersion = "12.1.4";
    SystemImageID = "F67A43D3-2ED4-4776-9A03-B23B4F809363";
}
[*] __assert(2:"BuildVersions match"==NULL)@JailbreakViewController.m:1175[jailbreak]

Please add an option to remove the com.apple.os.update-MSUPrepareUpdate snapshot.
unc0ver-b41-iPhoneX.log

[Scouseyerr]

Open uncover untick disable auto updates run the jailbreak then when it reboots the software update will be there then put in airplane mode and delete the iOS update an run jailbreak normal

[Scouseyerr]

Because the new iOS has not fully downloaded but it is there and when you run jailbreak it disables updates but doesn't delete the partial file

[TheChatty]

Thanks for the tip! Disabling auto updates enabled me to search for an update again. Then I could initiate official update process again, interrupt it by going into airplane mode. Then I could restore RootFS with unc0ver and start normal jailbreaking all over.
So after a lot of reboots I've got a jailbroken iPhone X still on 12.1.2. Thanks @Scouseyerr for the tip, thanks @pwn20wndstuff for the nice jailbreak!

[TheChatty]

Problem solved.

[TheChatty]

@pwn20wndstuff: Because you recently suggested to restore to 12.1.1b3 - it's not necessary (see above).

[topaztopaz]

Hello I am having the same issue but there is no OTA download. Help?!