Looks like you have a broken database or installation.
I experienced that also and here’s what I did.
I backed up all the users, the plugins I needed, themes & ect.
Did a fresh brand new installation.
Installed Tiny. Made sure it worked.
Manually installed one Plug-in at a time and tested Tiny every time to make sure the plugins are not breaking it.
Finally find out which Plugin is breaking your Tiny. What happens is that something gets broken by a plugin.
Then throw that Plugin out and install the rest in the same manner.
It’s time consuming but it’s the best way to debug your plugins.
GL.