this is a post just to share my experience with astrometry.net solver in order to get it to run. I ran the offline solver on my old Dell Inspiron laptop with Kubuntu 14.04, 64 bit installed on SSD. When I tried to use the solver recently inside Ekos, it always chrashed with an "Invalid instruction" error. Actually it was solve-field that crashed. Thanks to the guys on Astrometry.net forum I found a hint to compile it with optimization turned off, which was indedd desribed in the makefile. After doing so platesolving went fine.