Perhaps the hard-coded source variables pertaining to active open files need to be increased, I suspect a low arbitrary coded max on open files is the culprit in the coding.
There's no open files max coded in the program. That error is coming directly from your operating system. If you're on linux, check out the
ulimit
command.
You can also directly monitor the file system interaction via the Help Menu > Diagnostics. There's a complete log of all communication between Tixati and the filesystem in there, and also tons of charts and other fun stuff.