Error during upgrade1 user found helpful
Tried to update from 8.4.5 to 8.5.0
Got error during the prosess and everything is down.
The fault message is:
Whoops \ Exception \ ErrorException (E_COMPILE_ERROR)
Cannot use Exception as Exception because the name is already in use
I will be grateful for any help
I remembered reading in the 8.5.0 Release Notes about automatically changing the database collation to UTF8mb4. The error is related to this so I went into phpMyAdmin and changed the collation there:
Go to Operations tab, find the Collation option, select "utf8mb4_general_ci" from the list and select "Change all tables Collations".
I still had problems, and needed to upgrade to php7.1 in order to get the website working.
Hope that helps :-)