'There was an error! Your changes were not saved' error when trying to save the changes to a record in Outreach
Outreach records (Prospects, Opportunities, Accounts)
Check for any signs of an unsupported value being present in any of the other fields in that records (should be indicated by the value being in red letters or by another error message next to the field itself).
If so, correct that value (make sure to enter a supported value in the supported format).
The presence of an unsupported value or unsupported format in one or more fields of the Outreach record that the user is trying to edit.