illegal characters in path

When I use the save function, I get the error "Error saving Model. Illegal characters in path." If I then use the 'save as' function' I can save the file.

After this, neither the 'save' nor the 'save as' functions work. The system does not respond in any way when these functions are selected.

If I close BizAgi and open the "save as" file, it opens without errors and I can edit the model.

To save edits, I can only use the 'save as' function, then close BizAgi and re-open the 'save as' file.