Hi @Mohamed Abdullah ,
If all users are facing this issue, the root cause related to a server issue as the following:
- Memory usage is very high.
- SharePoint Search Host Controller service started and consumes a lot of memory.
- The database drivers are full.
- Anonymous Authentication disabled in IIS.
- “minFreeMemoryPercentageToActivateService” attribute is not set in the serviceHostingEnvironment tag in Web.Config.
- There is an issue in the SecurityTokenServiceApplication.
- The farm is not updated with at least Public Update / Service Pack 1.
If a specific user is facing this issue, the root cause related to the following:
- If your list has unique permissions, and a user/group has permissions only on that list and the user has limited or no access to the site level, then you will run into this error.
- Some free add-on like download manager may raise this issue.
Please confirm your issue and use related solutions to solve the issue in below article:
Note: Microsoft is providing this information as a convenience to you. The sites are not controlled by Microsoft. Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. Please make sure that you completely understand the risk before retrieving any suggestions from the above link.
If an Answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.