@elextr IIRC the UNC path for a SMB share is like `\hostname\share\further\path\components\file.ext`. To be honest, I don't know whether it is possible to use such paths in Geany and I cannot test. Though, I guess using files from SMB shares directly in Geany is less common than opening files from drives other than C: and even if, SMB shares can be mapped to a drive letter and then handling in Geany should be fine again.
I'll prepare a PR for the change to not use `g_path_skip_root` on Windows.