[MP2]

I wrote this test filterscript and ran it, and it worked fine:

pawn Код:

#include a_samp

public OnFilterScriptInit()
{
    new dest[128];
    new source[] = "Hello World!";
    
    strmid(dest, source, 0, 5);
    print(dest);
}

Outputs "Hello".

Perhaps you're using it wrong.