and there is no excuse why I should not be able to render multiple frames simultaneously on my computer. (I paid for a decent computer and im paying adobe's software)
This tells me you don't understand MP rendering at all and have not checked the numerous threads on the subject. It only works properly in a few situations. First your codec, the format you render to must be compatible with MP rendering. Most are not, and that's not Adobe's fault. Second, you must be using plug-ins that are optimized for MP rendering. The list is short and does not include many 3rd party plug-ins. Third, MP rendering settings are very easily screwed up by incorrect memory settings.
Without knowing anytnhing more about your project than the render is failing and you have an SSD drive, a bit of memory and Windows 8.1 there's no way to tell what to do to fix the problem except to turn off MP rendering, allow enough ram for other operations to stay running while your system is running, make sure your AE software, GPU drivers and plug-ins are up to date.
Hmm, thats wierd since I have been checking "numerous threads" on the subject and no, I might not know a lot within the subject. Still I have been talking to adobe support about the subject, they have taken over my computer via teamviewer and they dont even know.
*Same codec: quicktime (animation).
*Both when exporting and rendering in timeline
on my Windows as well as on my Mac
I have been searching google/adobe a lot but I might have missed something except the usual: "Did you update your after effect t the latest version" or "did you turn on your computer before trying to use it"?
So I have been looking and Ive been having contact with Adobes techincal support and yet they dont know what the issue or what might cause it duo to my situation. The conclusion from your comment "tells me THEY don't understand MP rendering at all and have not checked the numerous threads on the subject"
Why im asking here is to get help, I'm no expert, thats why I turn to the forums. If I need to specify more info about the project or anything else than Im more than willing to do so. If you want to help me I appriciate it, if you dont want to help then dont..
A very good response. It seems to me to be this way as well.
AE might as well output a reason in the log, naming the part that blocks MP rendering.
If not, there's just no way of knowing.