Problems of mirroring sprites

[nwfb1657]

HELP, After i mirrored some sprites...
After i mirrored some sprites on DRLF2
I found that some of the dat files have appeared erro errors
It said that sprite does not exist
So the game close itself
But actually that sprite exist and.it is in the accurate position
I tried resizing that sprite and this time it works
at the same timeProblems of mirroring sprites
another dat file got the same problem
so i wonder
is this related to my Ram capacity
My pc.only got 2GB ram
If i got a 8gb or 10 gm ram pc
will i solve the problem
please help