Issue with Random Signature Failures

The customer keeps getting random OneSpan signature failures when users try to send a document for signature. The same transaction works sometime and not others.   

1. Is there documentation of the error codes from Onespan and possible causes ? 

Here is a sample error returned from OneSpan rejecting the package, but the message is cryptic as to the cause.

“Number of Pre-Verify results does not match the number of documents that were sent for Verification”

Also is there a way I can loop the customer into this post and provide you information discreetly. They have a status line and will get some transaction ID's.

Should we create a support ticket for this as well?

Thanks