DraStic

My Pokemon Pearl crashes everytime at a battle with a trainer now and I don't know how this is possible. However, i got a notification several times that my phone was low on memory. Could this be part of the problem? And how can i fix this issue?

Phone specs: Sony Xperia Z1
OS: Android Lollipop

If it says you're running low on memory that's probably not a good thing. If you go in Android to settings->device->storage->apps->running you can get a summary of how much RAM is being used and how much you have available. Then you can get a listing of which open apps are using what RAM.

For DraStic itself, make sure you have the option set to uncompress ROMs to storage (it's on by default) or use uncompressed ROMs. Hires mode and shaders all consume extra RAM so you can try turning those off. You can look at the apps listing while it's running to get an idea of how much RAM it's using.

I checked it but can't see how much RAM DraStic is taking but what i do see is that without DraStic i've got 531 mb RAM free, which is almost 1/3 of the total RAM. Any other solutions? I've been playing this game for a while now and this is the first time this happens. I can't play the game anymore at the moment.

531MB is really not a lot of free RAM. For comparison my Nexus 4 has 1.3GB free right now. It's possible whatever is sucking up all that RAM is only sucking up more after DraStic runs.

If you get the error when it happens it simply means you were on the hairy edge before and one small allocation pushed you over.

Is your ROM zipped? Do you happen to have "Enable uncompress to file" disabled?

And I'm assuming there weren't any obvious other apps using a lot of RAM?

Egon Android loves memory leaks. A lot of apps and sometimes launchers themselves can cause them. The best thing to do is turn off your phone at least once a day until you find the app that is causing the memory drain.