so there is the problem
TRISC = % 10000000

portc pin 6 is set as an output
the latc.6 value is undefined but obviously 0

when tx module is disabled the pin reverts to be an output driven low , hence framing error
tumble weed pointed this out twice

and i said in post#2
if you used a decent chip you could make the tx pin open drain and not need this sort of worry