AC R12 to 134a Help for 1992 Seville

I bought this Interdynamics kit to convert and charge the air conditioning in my 1992 Seville. I put the fittings on and all seemed to go well except a couple things. First the warning in the instrument panel says " Regfrigerant Very Low, AC Compressor Turned Off." Secondly I pulled the fitting of the refill can off and everything I've added spews out. It's as if the a valve has not let the refergerant into the system. I tried turning the key off and unplugging the low pressure sensor but to no avail. So I ask if someone knows how to clear the compressor error to allow it to operate and possibly this will cure my problem of not letting my referigerant into the system. Can someone help me?

Thanks!
-Greg