Users who do not have Contribute on the root site are not able to run workflow 2013 . Error "Access denied ..."

Question

I have the following case inside our SharePoint online root site collection:

1. Members SP Group >> with Contribute permissions >> contain only UserA & UserB
2. Readers SP Group >> with Read permissions >> Contain Everyone except external

3. Inside the root site, we have a custom list which have a unique permissions (Contribute for all), where it got this permission:-

   • Members Group >> with Contribute permissions >> contain only UserA & UserB
   • Readers Group >> with Contribute permissions >> Contain Everyone except external

4. this custom list has a list workflow 2013 which get triggered when items are added and modified.

now if userC (who is a reader on the root site and contributor on the list), create a new item inside the custom list, then the workflow 2013 will raise this error:

Activity in progress

Retrying last request. Next attempt scheduled in less than one minute. Details of last request: HTTP Forbidden to https://*******.sharepoint.com/_api/web/lists(guid'95f1cccb-8f6f-46f6-89c8-91046a3436cd')/Items Correlation Id: 4590651d-d586-53c6-a024-6fe29fbc91a7 Instance Id: d19ac710-3665-4bdc-b4fb-d437e8877a9c

Access denied. You do not have permission to perform this action or access this resource.

so why is this happening? now if i grant userC contribute on the root, the workflow will run without errors... but i do not want userC to have contribute on the root site

Answer 1

Cause

Workflow is throwing this error because your end user is not having permission on a list whose GUID is 95f1cccb-8f6f-46f6-89c8-91046a3436cd.

Probably this list is the workflow history or workflow task list associated with your workflow OR any other list you are using in your workflow actions.

Solution:

1. Identify the list with GUID 95f1cccb-8f6f-46f6-89c8-91046a3436cd in your SharePoint site.
2. Grant the permissions to the end users on this list.