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USPS PostalOne! giving error 7175 "The MailPiece Unit Name {1}, Mail Piece Unit ID {2} and Segment ID {3} is not nonprofit authorized." after using MailStream Plus

MailStream Plus™, all versions, all platforms
4-Byte error codes received from PostalOne! are in the USPS's Mail.dat Technical Specs, which can be found on-line.  For example, search for "USPS Mail.dat Technical specs" 
As of May 2019, the current one is January 13 2019, located here-
https://postalpro.usps.com/mnt/glusterfs/2018-12/USPS_Mail_dat_Tech_Spec.pdf
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To find a specific error, do a search for the 4-byte number.  

For this issue, the number was 7175.  Per the document, the error message is-
The CRID {1} of the Permit Holder with the MailPiece Unit Name {2}, Mail Piece Unit ID {3} and Segment ID {4} is not nonprofit authorized.

And the Action to take is-
When the .mpu Mail Piece Unit – Rate Type is N = Nonprofit, please provide a nonprofit eligible Mail Owner in one of the following fields; .cpt Mailer ID of Mail Owner, .mpa Mailer ID of Mail Owner, .cpt CRID of Mail Owner, .mpa CRID of Mail Owner, or .mpa Mail Owner Lcl Permit Ref Number/ Int’l Bill Number and .mpa Mail Owner Lcl Permit Ref Number / Int’l Bill Num – Type

Which may not sound helpful, but actually what happened was that in mid-late 2014 the USPS required mailers to link their Non-Profit Authorization to their Mailer ID and/or CRIDs and/or Permit(s).

This mailer had not done that yet, which lead to the error message.  The mailer then called the PostalOne HelpDesk at 800-522-9085, and the HelpDesk was able to link the mailer's non-profit authorization to their permit, and that resolved the PostalOne! error.
UPDATED:  May 15, 2019