[Koha] Reinstall Koha

As I reported earlier on 6/14/21 at 4:54pm, I updated Koha from 20.11 to 21.05 and it had errors.  I tried Mr. Citali C.S.'s suggestions and it didn't work.  Right now I'm down.  This is my personal library. I have another installation at 20.11.03 which I am afraid to update.  This is a library which is in use daily. Is there any way I can dump my own library and install the current stable version then re-add my items? -- Bob Ewart