Symptoms

We have a workflow that triggers on document check-in on SharePoint. It is currently giving an error on the first step when it is trying to collect the metadata. The error says the lookup threshold is exceeded, but it is not. This was working and nothing on the library or workflow have changed since it was working last. We have 1 lookup column and 9 managed metadata columns. The threshold in our environment is 12.
 

Diagnoses

This happens when a link between the SmartObject and the Workflow is disconnected.
 

Resolution

Redeploying the workflow resolved the issue.