pages quit unexpectedly
I use MacOS Big Sur 11.0.1 therefore I updated to pages 10.3.5 and it only worked for a day. Now every time I try to open any Pages file a window pops up and says "Pages quit unexpectedly". Although when I want to open a Word File with Pages it works. It also works if I copy the Pages file to an external hard disk and open it from there in Pages. When I send a Pages file to someone that uses iPhone it's showed as zip file to the person receiving it.
I tried every troubleshooting I found online (cleaned cache, cookies, tried opening through safemode, FirstAid troubleshooting, tried changing the format .txt .doc or .zip and back to .pages, tried opening via different apps, looked if the files are locked, went to Library/Containers and deleted com.apple.iWork.pages) but nothing works.
Please help!
I did not do a backup therefore I cannot downgrade.
MacBook, macOS 11.0