Aslam Alaikum(Hi) everyone,
I had this error after running updates on my WP site, I have recovered it from the cpanel by following these steps:
1: Login your cpanel account.
2: Here you need to open online file manager.
3: Open the folder “htdocs”.
4: Now open “wp-content”.
5: Now sort this folder by “Time & Date” (On top menu).
6: You can see the most recent date folder, open it and delete the most recent updated folder. (It may be in theme, plugin, upgrade folder)
So this is how i solved my problem. You can try this.