Receive the error message “ORA-01435: user does not exist” on query execution. (4275832)

Execute or run a query statement and get the error: “ORA-01435: user does not exist”.

The USER exists and is the current session schema.
The Current Schema is specified in the select.
Receives a popup of error: ORA-01435: user does not exist
After clicking OK, the correct results are displayed.
Clicking "Details >>" on the popup provides no further details, but displays the same error message.
It occurs in both DML and DDL, by F9 run as well as F5 Execute As Script, the windows is slightly different.
It has happened with every username logged in with.