> and the crash repoort page for Adobe doesn't seem to exist anymore
There is no "crash report page". The crash reporter is the dialog box that opens when a crash occurs that allows you to send the crash report to us.
There is a bug report page.
You didn't say which version of After Effects you're using. Have you installed the recent updates? They fix a lot of problems.
> Also, how can I backup my preferences and workspaces as well?
The "Preferences" page of After Effects Help tells where the preferences files are stored.
> What could be causing this?
It's hard to say with so little information.
In addition to what specific version of After Effects you're using, we need to know a lot more if we're going to help. What kind(s) of source footage? What were you doing when the problem occurred? Has this ever worked before? What other software are you running? Do you have any third-party effects or codecs installed? Tell us about your computer hardware. Are you rendering with OpenGL? Is the probem happening when rendering to final output? During RAM preview? Are you using Render Multiple Frames Simultaneously multiprocessing? What are your memory and multiporcessing settings?
I recommend you use Sysinternal's Process Monitor to create a log. Set it to filter on AfterFX.exe and let it do its thing with an automatic log backup. This could provide some clue as to which specific thing is causing the issue. Also make sure to set AE's render logging to extra info per frame and possibly use AE's own logging to gather forther information - create an empty file called After Effects Log.txt in your user configuration directory. In any case, I think you eitehr have a critical file I/O issue here and run out of (temporary) disk space or it's a driver crash either in the graphics card or, if audio is used in the project, the audio hardware.