HELP Error: reference to invalid character number at line 5

i was just playing around with audacity recorded a few clips, and then i click the cut button by accident then everything dissapeared, i tried undoing but it didnt work and everytthing was just gone, and then i re opened audacity and now its saying this,. iw

Please attach the AUP file to your reply. I expect that it is irreparably damaged in some way, but can’t say more without seeing the AUP.
See here for how to attach a file to your reply:

Have a look at this FAQ in the updated Manual for the upcoming 2.2.0

When you eventually get 2.2.0 you will see that when you get that error message there will be a Help button “?” which will take you to that page in the Manual.

Note carefully that while the page I sent you her applies to earlier Audacity versions too not all of that draft Manual does - there’s a lot of new stuff …