https://bugs.winehq.org/show_bug.cgi?id=36859
--- Comment #17 from Jeremy White jwhite@codeweavers.com --- (In reply to panzerito from comment #16)
Created attachment 53066 [details] +file,+relay wine-1.8-rc3 with with GetLongPathName patch
ERROR: Missing Shader 'shaders/font.ksh'
wine-1.8-rc3$ diff dlls/kernel32/path.c dlls/kernel32/path.c.orig
337c337 < if (!lp || (tmplongpath[lp-1] != '\' && tmplongpath[lp-1] != '/'))
if (!lp || tmplongpath[lp-1] != '\\')
339,340c339,340 < /* strip double delimiters */
< tmplongpath[lp++] = shortpath[sp];
/* strip double "\\" */ tmplongpath[lp++] = '\\';
My Don't Starve is GOG's version updated to 151567.
Sure enough, you have a different failure than I do. It appears to be legitimately not finding the shaders file. It might be worth fiddling with your current directory prior to invoking Wine. That is, cd to the directory that contains the 'shaders' directory, and run Wine from there. (If you go to line 127527 in your log, you'll see that GetLongPathName returns 0, which is essentially a failure. You can see the files it was looking through to give you a hint of where it was trying to find shaders/font.ksh in).
Since I don't have the GOG version, I can't troubleshoot further.
You might also try a clean reinstall of the game from GOG; I noted that you had been moving files around, and is it possible something got accidentally moved and not returned?