While trying to add a new fe_users record, on save I get
(1/1) Exception
Could not determine pid
It's TYPO3 9.5.20.
We already have a lot of entries in multiple folders which could be edited without problem.
But those records were imported (by EXT:ig_ldap_sso_auth or with mysql terminal)
These records are used only to be shown (no login is used).
What configuration is missing or could be wrong?
EDIT:
as @biesior mentioned: the error message does not come from the core but from an extension. It's EXT:solrfal (in version 7.0.0)
The real error was not in EXT:solrfal. this extension just hides the error with a misleading message.
The real reason was a wrong database configuration for the table fe_users. Although it is not possible in SQL to have a default value for fields of type text (and any given value is ignored) TYPO3 expects a default value if it is configured. As this is not returned from the database it assumes an error. And EXT:solrfal hooks into the error handling and assumes a wrong error.