Mission loading hangs at 50%

[sigzegv]

This issue seems to be related to this point This might be caused by a Arial missing font which can not be distributed with Wine. in the README.
I don't really understand what action is required here because I have installed the corefonts from winetricks, and the windows/Fonts folders in the wine prefix already has fonts named arial*.ttf

And here is the log at the point of the crash

2021-04-05 15:37:03.964 ERROR   FLIGHT: Unknown runway side 08 of beacon IKS at airdrome KUTAISI
2021-04-05 15:37:03.977 WARNING LOG: 1 duplicate message(s) skipped.
2021-04-05 15:37:03.977 ERROR   DX11BACKEND: Can't load image 'missioneditor/data/newmap/images/themes/russian/beacon_with_marker.png'. Reason: Invalid parameter.
2021-04-05 15:37:03.978 INFO    UIBASERENDERER: Cannot load font []!
2021-04-05 15:37:03.978 INFO    EDCORE: try to write dump information
2021-04-05 15:37:03.979 INFO    EDCORE: # -------------- 20210405-153703 --------------
2021-04-05 15:37:03.979 INFO    EDCORE: DCS/2.5.6.61527 (x86_64; Windows NT 6.1.7601)
2021-04-05 15:37:03.979 INFO    EDCORE: C:\dcs\bin\DCS.exe
2021-04-05 15:37:03.979 INFO    EDCORE: # C0000005 ACCESS_VIOLATION at 408A0C17 00:00000000
2021-04-05 15:37:04.759 INFO    EDCORE: SymInit: Symbol-SearchPath: '.;C:\dcs;C:\dcs\bin;SRV*c:\websymbols*http://msdl.microsoft.com/download/symbols;', symOptions: 530, UserName: 'cavern'
2021-04-05 15:37:04.760 INFO    EDCORE: OS-Version: 6.1.7601 (Service Pack 1) 0x0-0x1
2021-04-05 15:37:11.004 INFO    EDCORE: 0x00000000008A0C17 (dcs): (function-name not available) + 0x0
2021-04-05 15:37:11.005 INFO    EDCORE: 0x000000000089322D (dcs): (function-name not available) + 0x0
2021-04-05 15:37:20.260 INFO    EDCORE: Minidump created.
2021-04-05 15:37:20.261 INFO    DCS: enumerating loaded modules
2021-04-05 15:37:20.262 INFO    DCS: C:\dcs\bin\DCS.exe, 18610608 bytes, created 8:3:2021-8.54.26, written 8:3:2021-8.54.26, accessed 4:4:2021-0.22.59
[...]
2021-04-05 15:37:21.018 INFO    DCS: try to write track file
2021-04-05 15:37:21.024 INFO    DCS: 'C:\users\cavern\Saved Games\DCS\Logs\dcs.20210405-153703.crash' deleted successfully
2021-04-05 15:37:21.064 INFO    DCS: 'C:\users\cavern\Saved Games\DCS\Logs\dcs.20210405-153703.dmp' deleted successfully
2021-04-05 15:37:30.489 INFO    DCS: failed to open 'C:\users\cavern\Saved Games\DCS\Logs\voice_chat.log' for reading

[ltodoto]

I had the same issue (the message UIBASERENDERER: Cannot load font [] right before crash report part of the log).
To fix the issue, I had to manually copy the TrueType font files for Arial, Arial Bold, Arial Bold Italic, Arial Italic to the drive_c\Windows\Fonts directory inside the wine prefix. The files themselves don't have to be of the Arial font family, as far as I'm concerned (i. e. substitutes should work too, although I've used the ones from mscorefonts package). The important thing is: target files must be named as follows:

arial.ttf
arialbd.ttf
arialbi.ttf
ariali.ttf