Could you try disabling Firefox's hardware graphics acceleration? Due to some recent driver updates, many users are experiencing strange performance and stability issues linked to this feature.

You usually need to restart Firefox in order for this to take effect, so save all work first (e.g., mail you are composing, online documents you're editing, etc.).

orange Firefox button or classic Tools menu > Options > Advanced

On the "General" mini-tab, uncheck the box for "Use hardware acceleration when available"

If you restart Firefox, is the issue resolved or at least improved?

this seems to solve the problem. but why does the hardware accelaration crash firefox?