Symptoms

• Remote verification station
• Custom action
• Usage of IDocument.SaveAs() method

Cause

• Usage of this method is prohibited on Remote and Web stations.

Resolution

It is strange, but the original message has nothing in common with the page limit of your license.

The Remote Verification station has a limited potential, comparing to the rich Verification station.  Differences are described in our help:
https://help.abbyy.com/en-us/flexicapture/12/distributed_administrator/differences

Moreover, the SaveAs button doesn't present in GUI on the Remote Verification Station:

Which implies for inability to use the corresponding script methods as well.