Map too big to edit scenario?

Level 2
Apr 25, 2015
Hey guys, I hope you can help me.

I'm currently working on a map, and I set everything up, but after I edited the map in the newgen WE to a map size of 425x425 I cant edit anything in the scenario.
If i want to change anything and need to hit OK for it to accept the changes, it tells me I surpassed the map limit. (Too much cells)

How can I bypass this error? Other people have even bigger maps and I'm sure they had to change the loading screen later in development - but then you are stuck with your map size.

Thanks in advance! Have a nice day!