PLEASE HELP - Master code will not turn off alarm

[Grigs68]

I installed the Envisalink 3 in my DSC Power Series PC1616, registered the system and followed all the instructions. It appeared that everything was working. I then set my alarm from the panel by pushing the STAY button. Now when I try to disarm it the master code I have been using will not work. I have the installer code but that will not work either as long as the system is armed. Does the Envisalink 3 cause my alarm to reset the master code to something else? How can I turn my alarm off? I have already powered it down (battery as well) and when I powered it back on, the system is still armed. Please help.
Thanks

[Grigs68]

Still not sure what caused this but I did a complete system reset and so far, it appears all is working normally. Would still like to hear an explanation of what caused this if anybody has had this issue before.