When attempting to create new custom fields, a blank SFDC page loads with the message: Unable to Access Page. Or a message such as the following appears: No clean data columns available for custom fields.
While there can be multiple factors contributing to this issue. The most common one is if a custom field limit is close to being reached on an object. Some fields get deleted, then shortly after new fields are added in a slightly larger quantity than the amount deleted. This happens below the limit count.
Example from SFDC:
There is a limit of 100 fields per object and approximately 95 are being used all the time. On the same day 10 fields are deleted and 15 new fields are being created due to business requirements. The error occurs as the fields that were removed were not hard deleted.
- Navigate to Setup --> Object Manager.
- Scroll down to Fields and Relationships.
- Click Deleted Fields at the top to view deleted fields.
- Empty the Recycle Bin.
- If the steps above to do not work, enter a ticket with Veeva Product Support.
SFDC Help Documentation: N/A