Unable to Save Changes After Editing the Properties of a Document in Sharepoint Document Library

I experienced a problem with one of my customers that the changes she made after editing the properties of a document in the Document Library of Sharepoint was not saving!

The solution? Check the Content Type of the Document Library is using and check the columns for any duplication. Delete any duplicate columns at it will solve the problem.

To check the Content Type make sure you enable the management of content types. To enable go to Document Library settings -> Advance Settings then choose YES on "Allow Management of Content Types".

After that, go back to the Document Library Settings and click the Content Type that the Document Library is using to check the columns.

Again, delete any duplicate columns. It works on me so I hope it will work on you too.