I have option ui_one_instance too. Portable version. Use Windows 7. And the problem with saving/not saving yesterday repeats one more time. On v.1.105.0.0. It seams problem occures in random time?
Possible case in code an exception not correctly handling by common exception handler?
[no repro] Issue with saving
I can not write steps. It happens by accident. Both time I had problems - I was working with Sublime Text Color Scheme (xml type) files. I just did edit and undo actions. And files was not saved as result. It starts when I start use CudaText v1.103.1. I use Windows 7, portable version and no any plugin.
It sounds like solved issue
https://github.com/Alexey-T/CudaText/issues/2677
try in release 1.105.5.5.
https://github.com/Alexey-T/CudaText/issues/2677
try in release 1.105.5.5.