now that is a really strange one, try back up the file then use the main menu File>Utilities>Rebuild and Verify run it as many times as necessary (but at least 3 times) until it completes, then close QB and re-open it and see if it helped

Resolution for 'change it back issue: 'The “Class” columns under “Enter Bills” was moved to different column, and I would like to change it back.' available: Yes.

The change it back issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the change it back issue yourself by looking for a resolution described in the article. If it is a complex change it back issue or you are unable to solve the issue, you may contact us by clicking here or by using other change it back support options.

For more information about resolving issues related to change it back in Quickbooks/QBO or to get support for the issue 'The “Class” columns under “Enter Bills” was moved to different column, and I would like to change it back.', click the link below: