The player starts but the all the text is missing:

Install and play MermaidVR
Needs mono and ffmpeg
$ mono --version
Mono JIT compiler version 5.16.0.179 (tarball Thu Oct 4 10:20:38 UTC 2018)
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
TLS: __thread
SIGSEGV: altstack
Notifications: epoll
Architecture: amd64
Disabled: none
Misc: softdebug
Interpreter: yes
LLVM: yes(3.6.0svn-mono-/)
GC: sgen (concurrent by default)
$ ffmpeg -version
ffmpeg version 4.0.2-2 Copyright (c) 2000-2018 the FFmpeg developers
built with gcc 8 (Ubuntu 8.2.0-7ubuntu1)
configuration: --prefix=/usr --extra-version=2 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
libavutil 56. 14.100 / 56. 14.100
libavcodec 58. 18.100 / 58. 18.100
libavformat 58. 12.100 / 58. 12.100
libavdevice 58. 3.100 / 58. 3.100
libavfilter 7. 16.100 / 7. 16.100
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 1.100 / 5. 1.100
libswresample 3. 1.100 / 3. 1.100
libpostproc 55. 1.100 / 55. 1.100
Still doesn't show the text.
@h1z1 it looks Unity-based, why do you think it's need wine-mono (you meant wine-mono, right?)
@leinardi please test with 3.16-4, it's possible it's fixed now.
@nsivov the text problem seems solved (great work!) but it is not able to play any video.
Now it's probably a quartz.dll issue.
Edit: probably benign mention of Quartz.
~It looks quartz related, from the log from @leinardi at https://github.com/ValveSoftware/Proton/issues/1799#issuecomment-434980900~:
1608.486:0024:00dd:trace:module:get_load_order got hardcoded default for L"quartz.dll"
1608.486:0024:00dd:trace:module:get_load_order looking for L"C:\windows\system32\quartz.dll"
1608.486:0024:00dd:trace:module:load_builtin_dll Trying built-in L"quartz.dll"
1608.486:0024:00dd:trace:module:load_dll L"C:\windows\system32\quartz.dll" is a fake Wine dll
1608.486:0024:00dd:trace:module:load_dll looking for L"C:\windows\system32\quartz.dll" in L"C:\windows\system32;C:\Program Files (x86)\Steam;C:\windows\system32;C:\windows\system;C:\windows;.;C:\windows\system32;C:\windows;C:\windows\system32\wbem"
1608.488:0024:00dd:fixme:quartz:FilterGraphInner_QueryInterface unknown interface {00000003-0000-0000-c000-000000000046}
1608.488:0024:00dd:trace:module:load_builtin_callback loaded quartz.dll 0x76b8960 0x7f1582290000
1608.488:0024:00dd:trace:module:load_dll Loaded module L"C:\windows\system32\quartz.dll" (builtin) at 0x7f1582290000
1608.488:0024:00dd:trace:module:MODULE_InitDLL (0x7f1582290000 L"quartz.dll",PROCESS_ATTACH,(nil)) - CALL
1608.488:0024:00dd:trace:module:process_attach (L"quartz.dll",(nil)) - END
1608.488:0024:00dd:trace:module:process_attach (L"quartz.dll",(nil)) - START
1608.490:0024:00dd:fixme:quartz:FilterGraphInner_QueryInterface unknown interface {00000019-0000-0000-c000-000000000046}
1608.793:0024:0100:fixme:quartz:StdMediaSample2_QueryInterface No interface for {f940ae7f-48eb-4377-806c-8fc48cab2292}!
Last sample fixme is about LAV Filters custom interface, it's not something quartz has to support.
@nsivov What is LAV Filters? I'm not sure what that means... From a bit of googling it's some kind of splitter/decoder for media files? Wouldn't that point to quartz media troubles?
This line has quartz and media in the same line? Isn't that relevant then?
1608.793:0024:0100:fixme:quartz:StdMediaSample2_QueryInterface No interface for {f940ae7f-48eb-4377-806c-8fc48cab2292}!
I thought it was Quartz media related so I added it to my list at #1464, but if this is completely off-base I'll delete it of-course. :+1:
LAV Filters is a project that's using quartz, while implementing additional API, this fixme is for that additional API. Just pointing out that this particular message is probably benign.
@nsivov I'll delete the entry from my list at #1464 then, seeing as the quartz mention is probably benign. :+1: Thanks for the explanation.
Linking project page, just in case we'll need to come back to that https://github.com/Nevcairiel/LAVFilters.