The generator matrix

 1  0  1  1  1 X+2  1  1  0  1  1 X+2  1  X  1  1  1  X  1  1  1
 0  1 X+1 X+2  3  1  0 X+1  1 X+2  3  1  0  2  X  2  X X+2 X+3  1  0
 0  0  2  0  2  0  0  2  0  0  2  0  2  2  2  0  0  2  0  2  0
 0  0  0  2  2  2  2  2  2  0  0  0  2  0  0  0  2  2  2  0  0

generates a code of length 21 over Z4[X]/(X^2+2,2X) who´s minimum homogenous weight is 18.

Homogenous weight enumerator: w(x)=1x^0+7x^18+58x^19+35x^20+86x^21+7x^22+38x^23+9x^24+10x^25+1x^26+2x^28+1x^30+1x^36

The gray image is a code over GF(2) with n=84, k=8 and d=36.
This code was found by Heurico 1.16 in 0.00295 seconds.