So, you're (kinda) emulating Windows on a Linux virtual machine running on Chromebook?
Imho, too many layers. If you used the binaries I've linked (assuming you own a x86 chromebook), I think you could do without Wine: better performances and fewer errors.
If you prefer to play with Wine, try to open this directory in your Linux virtual machine:
$WINEPREFIX/drive_c/users/[YOUR_ACCOUNT]/Local Settings/Application Data
or something like that (the actual path depends on what Wine is "emulating", if Windows 10 or something else).
There should be two folders inside: "User Data" and "KADOKAWA". Maybe their data are corrupted. If you rename them, RPGM should be forced to re-create them from zero (hopefully, without errors). No promises, because I've never seen the bug you've experienced.