Unable to edit List items in SharePoint

For existing list, please follow the below steps to resolve the issue.
1. Download “SharePoint Manager”
2.Launch “SharePoint Manager” from SharePoint App Server by logging with Farm Admin account.

3. Expend the respective site and then list.

4. Scroll down and select the field value.

5. Click on the button in front of (Collection) text.

6. Scroll down and select the "Effective Permission Mask" and "SxchemaXml".

7. Copy the "SchemaXml" value.

8. Add the value RenderXMLUsingPattern="TRUE"

9. Overwrite the value and click OK.

10. Now you should able to edit the items in the list.