Hi CRTRZB,
Thanks for posting in the community. We are happy to help you.
I have read your post carefully. However, I still have some questions about the situation you describe. Therefore, I would like to confirm the following points to you before making any suggestions.
- Regarding the thread title, you cannot edit or delete an existing calculated column. I would like to know if the error message appears when going to the Edit Column page as shown below.
Generally, you can go to the list, click Settings (the Gear icon) in the upper-right corner> List settings. On the List settings page, under the Columns sections, click on the relevant Calculated column and then click on the Delete button.