2004 GMC Yukon P0300 Error

I have a 2004 GMC Yukon which had original spark plugs and wires, but was
running fine.  We just changed all the spark plugs, but I forgot to use anti-
seize on the plugs during installation.  We are getting the P0300 code (x2, 1
send "PEND" and 1 said "MEM").  What are the odds this is caused by 1 of
the following?

1) We were given the wrong spark plugs by AutoZone. We bought the Bosch
Double Platinum 8104 pre-gapped plugs.
2) The lack of anti-seize is causing an issue.
3) I installed them too tightly and they are too far into the cylinder.

Any help would be great.