Error:20 Unsupported or invalid g-code

thx for reply.

I am connected via wifi, this is the offending command: M4

G00 G17 G40 G21 G54

ok

ok

G90

ok

G0 X2 Y2

ok

G91

ok

M4

error:20

Unsupported or invalid g-code command found in block.

EDIT:I have just seen this post:Another M4 error with DLC32 V2.1.003
It seems to be a firmware problem.
Very bad for me,as I had to compile the source code to invert the Y-axis pins with the Z-axis ones (on the board there are 2 connectors for the Y-axis,on my machine I have 2 motors in the Z-axis) so I will have to look for the bug,but I don’t know where