Hello All, 

I have a workflow that has been in place for years with no problems running. The workflow runs when an item is created. One of the actions that it does is after a query, it gets an item from the collection (simple step). 

For the past week, that action has been giving the index error for collection variable BUT it only does it when triggered by someone else. This happens EVERY time. 

I have created dummy items and the workflow works with no problem. After errors on someone else, I cancel the errored workflow and manually restart it and it works as well. 

Nothing changed in the workflow that would cause this to happen.

So far I have removed and them imported the workflow again and it still does the same thing. 

Does anyone have any idea why this would be happening?