I've just noticed this too in my X620-16x. VELOSO SFP+ transceivers give the same type of DDMI errors and Extreme Networks branded transceivers manufactured by OPNEXT, INC., FIBERXON INC. and FINISAR CORP seem to be fine. It's like the switch is lo...
I've found that you used to be able to type "debug epm enable trial" but now with XOS 15.4.1.3 the complete command "debug epm enable trial-license" is necessary. The same goes for "debug epm clear trial-license".
