How you produced the problem; In facebook and generally in pages with video content, when i try to view some videos, sometimes the page freezes temporarily and then it is released again but the content is black.
How you tried to resolve the problem; Temporary fix, kill plugin-container.exe child process and refresh page in IceDragon again
Screen-shots with the error (if any); Took a print screen but was a bit careless and lost the clipboard contents. Sorry. Will post it here later if error occurs again
Post Memory Dumps on crash if you encounter any; Process did not crash completely, only the rendering/plugins part apparently
Any other Additional Information; Will try to post in replies as soon as I have new information
Will post it here later if error occurs again