I opened an issue there (https://github.com/thentenaar/motif/issues/50) and it is fixed now.
No, I haven't changed anything.
I have seen that you created an issue on github about a similar problem: https://github.com/thentenaar/motif/issues/49 For me this looks 100% like a problem with this motif fork. It crashes directly at the start inside XtAppCreateShell. The reason xnedit crashes and other motif apps don't is probably that the fallback resource sets a custom render table, in the file nedit.c, line 174 to 182. You could try to remove that or modify the render table and see if this solves the problem. Whats weird is,...
Merge branch 'master' of https://github.com/unixwork/xnedit
Merge branch 'master' of https://github.com/unixwork/xnedit
fix default settings for Right Margin was not changeable
fix gaps in underline
fix width when drawing the underline style