ROM Hack Super Smash Bros Trimming

[midnight1001]

OK so just a quick question. I recently got a copy of Super Smash Bros European roughly 2gb in size. I tried to open it in 3ds Explorer but got the unhanded exception error saying that access to the location of the game was denied. However when trying another of my games in the same location they load up fine. My question is simply is super smash bros incompatible or has anybody successfully trimmed it down? The other thing is when i try to run rom_tools it loads up for about half a second before crashing... Any Ideas?
Thanks in advance

 

[piratesephiroth]

Either the rom is opened in another program os it's set to read-only.

 

[midnight1001]

Thanks so much! It worked. Turns out it was set to read only... Don't know why I didn't remember to check that.
Thanks again