Bug report - (Invalid characters in path.)

This error message generally comes up when you are trying to save a file that was previously restored. Meaning the program shut down improperly and then the file was restored. 

The problem is with the file name. If you look at the name at the top of the program it will say "file name , numbers numbers numbers, Restored from....2/6/2016 (or other date)" and so every time you are clicking the save icon, you are telling the program to save under that name that is in the above bar, and it can't do that with the " / "characters that are in the name. So, you need to "save as" some other name like Project name-2 and then as you go you can keep clicking the save icon, no problem. This problem only comes up when you are trying to save a restored file.