Vermeer 504 Super I baler

Good evening.  I need some help with an error code my Vermeer 504 Super I is giving... E 64.  I've owned it for 3+ years & it has always baled perfectly... Literally blonde proof.  When I put it up from last cut in May it baled perfectly.  Today when I hooked it up it won't tie & gives the E 64 code.  It's getting power to the actuator, it will "extend" to start tie & gets "stuck" there.  I can do a manual tie as long as I hold the extend button for desired time & then retract to just before the "cut" spot for desired time, then retract again for cut.  It is a dual tie.  I am doing twine, not net wrap.  It has a net wrap option, but is not set up for net at this time.  Any suggestions are GREATLY appreciated.  Thanks

Vermeer 504 Super I baler