Cannot change item-level permissions because this list or document library contains a column that enforces unique values - SharePoint 2010

User wanted to make some permission level changes on the survey. So that Users can read or edit only their surveys.

We went to the advanced settings. Tried to change it to

We got an error

"Cannot change item-level permissions because this list or document library contains a column that enforces unique values"

We then tried researching and then found that one column "Title"

had that option set to yes as below

We tried to make some changes in the same column from choice to single line of text and enforce unique values to no

However we got one more error.

"The type of this column cannot be changed because it is currently being indexed”

Ahhh... Now we first took a backup of the survey list.

We then created a new column which worked fine. Then deleted the Title Column

And we were able to make the changes.

We were able to now make the changes in the advanced settings. As there was only one column which had that option checked.

Product applies to:

SharePoint Server 2010

SharePoint Foundation 2010