I am getting a "The Stub file named "<...xxx...> is not valid" error.

This warning appears in some of our late builds as result of loss of connection to the SQL server. Please confirm the issue is intermittent or consistent when printing a Mekorma MICR Test Layout form. Then determine if the issue is intermittent or consistent in production. If the former or unable to reproduce this will confirm a temporary loss of data connection is the issue as Mekorma formats are stored in Mekorma SQL tables currently. We have reproduced the issue in-house when a data severance is induced.

Please take note of the Windows Event Viewer, under Windows Logs/Applications, look for the time that error(s) occurred look for Source MSSQL Server or the default name, and determine if you have any messages pertaining to status of the server whether on or offline for example. This should help to indicate if there is an issue with access to the SQL server. 

In future builds we plan to identify the problem such that the message will display more accurately the nature of the issue.

Also, this error occurred in older Mekorma versions when clients upgraded from a build that supports the .stb format to a build that only supports the .stbx format, you posted a payment that used a .stb format and you are trying to view it in the newer build using the GP Inquiry. This issue is fixed beginning with Version 2010 B300 and 2013 B100.