[dl-ticket-service] Not Acceptable error with SQL Server backup file

[Kelvin Smith]

Using DL v0.17.1 and either the Thunderbird add-on or a direct upload to 
the online ticket service, sending a SQL Server backup causes an error 
when I try to download it. I get the message:

"Not Acceptable!
An appropriate representation of the requested resource could not be 
found on this server. This error was generated by Mod_Security."

I've tried several different SQL Server backups (coming from SQL Server 
Express 2014 and 2012) with the same result. The files display in the 
All Tickets list; clicking on the Download button in that list gives the 
same Not Acceptable error message.

If I put the file into a zip archive, everything works normally. 
However, I'd prefer to be able to send the file directly. Any ideas on 
what's going on?

Kelvin Smith