Whenever I animate, the app crashes seemingly randomly. No other glitches happen, just that the app will hang and then close itself.
I ran it from the terminal to see what was going on, and the error that happens when the app crashes is “malloc_consolidate(): unaligned fastbin chunk detected”. What does this even mean?
Someone please help…
Hello @altostratus and welcome to the forum 
I don’t know what that error message means but someone else on the forum might know and reply soon.
Are you using the 5.3.4 appimage?
If not, I recommend that you do that, downloading it from here:
Download | Krita
After downloading it, give it Execution permissions by doing right-click → Properties on it then go to the Permissions tab and enable Execute. Then you can run it.
Do you try to make long, large and complicated animations?
Do you have any/many animated transform masks?
Or does this happen with short, small and simple animations?
I was using the Flatpak downloaded from the Software Manager app when my animation was crashing. The animation itself was very short and very simple, only one transform mask used.
Things seem to be running smoother with the AppImage though.
…coming back a few minutes later to update that the AppImage crashed too 
Was that a static or an animated transform mask?
Have you made animations in krita before with no problem and had this trouble recently, or have you only recently started to use krita?
What CPU does your PC have and how much RAM does it have?
How much free disk space do you have?
Are you doing any action in particular when the crash happens?
Do you have other applications running at the same time, such as a browser running with YouTube music videos etc.
Make sure there are no other applications running when animating with krita.
However, have the System Monitor running to regularly check and note the amount of RAM being used by krita and the free RAM remaining, to see if there could be a problem looming.
I think it was an animated transform mask
I’ve had Krita for a while but only just started using it for animation. I’ve mostly been making drawings and doodles.
My CPU is Intel(R) Core™ i5-10300H CPU and my computer has 16 GB of RAM
I have 144 GB of free disk space
The crashes happen randomly, so no, there isn’t any particular action that causes it as far as I know
The crashes happen even without any other app running at the same time
I’ve had System Monitor run so I could monitor my RAM usage, and Krita doesn’t use a lot of my RAM
There is a big difference between the demands of an animated transform mask and a simple static transform mask.
Your computer has more ‘CPU power’ than my 15 year old desktop PC and I don’t have crashes even with multiple animated transform masks acting on the same paint layer.
You have more than enough RAM and the System Monitor indicates that there is no ‘RAM use stress’ happening.
Your CPU has integrated Intel UHD graphics so I wonder if it’s problem associated with that.
I can’t think why this is happening.