[SickAttack]

possibly unintended bitwise operation
Where a conditional expression was expected, a bitwise operator
(& or |) was found instead of a Boolean operator (&& or ||). In
situations where a bitwise operation seems unlikely, the compiler
issues this warning. To avoid this message, put parentheses around
the expression.

tag mismatch
⋄ assigning to a tagged variable a value that is untagged or that
has a different tag
⋄ the expressions on either side of a binary operator have different
tags
⋄ in a function call, passing an argument that is untagged or that
has a different tag than what the function argument was defined
with
⋄ indexing an array which requires a tagged index with no tag or
a wrong tag name

http://www.compuphase.com/pawn/Pawn_Language_Guide.pdf

if(strfind(text, MG[i], true) != -1 & PlayerInfo[playerid][AdminLevel] == 0 && IsPlayerAdmin(playerid))

HINT: Replace "&" (red one above) for "&&".