When trying to update a workflow task item in code, you may get the error “This task is currently locked by a running workflow and cannot be edited.”
This error gets thrown because the ows_WorkflowVersion of the task list item has been set to 512.
There may be a good reason it’s set to locked (i.e. currently being updated) but it you really really want to still update the task, you can override the flag.
When trying to delete a site column, you may get the error “Site columns which are included in content types cannot be deleted. Remove all references to this site column prior to deleting it.”
This simply means that the site column needs to be manually deleted from content types before it can be properly removed.
You may have already manually done so on all content types you know of that refers to the site column, but the error still persists.
This is because it not only needs to be deleted from content types on the site collection level, but on all site level content types as well!
This issue is similar to the problem reported at https://social.technet.microsoft.com/Forums/office/en-US/50001a2f-bf80-44fb-b8c9-4835cc15b7f6/problem-with-metadata-navigation-key-filters-and-grouped-views.
The error happens when you’ve enabled the Metadata Navigation and Filtering feature, and configured a list with Metadata filters, and has a list view that is grouped by a column:
- If the Group By is set to Collapsed by default, then when you apply a Metadata Filter and expand a group, it brings back all items instead of filtered results.
- If the Group By is set to Expanded, applying a Metadata Filter works fine, until you go to the next page, and again all items are returned instead of filtered results.
While Microsoft released a fix for this in the SharePoint 2013 July 2014 CU, it seems that there is still 1 edge case where this error is happening:
- The Group By column you’re using is a Lookup field
As of March 2017, it seems to be happening in SharePoint Online as well.