I am using Screenshot Captor 2.57.01 on Windows Vista SP2. My IT department just moved my "Documents" folder to a UNC network path (e.g. \\computer\path\subfolder). This caused Screenshot Captor to crash whenever I tried to start it. It displayed a blank error dialog box and then closed.
I edited the ConfigDir.ini file and set the CONFIGDIR value equal to the . directory (e.g. CONFIGDIR = .) to tell it to save all configuration files in the program directory. I restarted Screenshot Captor and everything worked!