I went through the maintenance manual (version 14221-1200-5000, Rev. B) and the list of error codes starts on page 102. In the last actual terminal message that came into Putty was error code 509 "Increased Personality files are not present". I found it in the category "Personality Interface Fatal System Error Codes" starting on the bottom of page 104 and the full error code is 0x5509.
So far I have failed at getting it to respond again in the same way as in that Putty screenshot. Don't know which blindly sent command triggered the response as I was desperately trying everything in the command list. ;-)
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