1. Check the profile permissions for the user.
2. Issue may be due to the Picklist field value or if the record is locked due to Approval Process.
3. Check this known issue https://trailblazer.salesforce.com/issues_view?id=a1p3A000001SHxuQAG
4. If you are getting this error when clicking “Edit as Draft” button, query the field values and make sure the values are under the character limit for all the fields on the page layout.