Issue: In Datasheet sheet view, users unable to edit anything. Its in always Read-Only mode.
Check the following to fix SharePoint list in datasheet view is read only:
- Content Approval must be turned OFF (Microsoft KB: http://support.microsoft.com/kb/2274841)
- Some columns are dependent on Microsoft Access, check whether MS-Access is installed in the client machine.
- Check whether you have permission to edit
- The document in the current row may be checked out by a user.
- Attachments are read-only in a list that requires content approval. You cannot view or edit attachments in any of the views.
- Certain columns, such as Created By and Modified, are always read-only.
- There may be an unresolved conflict or error in the selected row or column. Resolve the conflict or error before attempting to edit the selected row or column.
Update: To use edit in Datasheet view, even with content approval turned ON, use my trick Edit in Datasheet View – Even When Content Approval is Turned ON