Been busy otherwise so I missed this message. I can give you the "why" but not a fix.
What is basically happening (I really don't understand the details either

) is that you are trying to write a file and the computer can't find enough "free" space to put it. This in fact can happen even if you have a lot of free disk space but are out of enough buffer memory to write a complete file. Memory management can't handle, for example, being only able to buffer half of a .jpeg frame - since the (somewhat dumb) compression algorithm needs the whole file.
You can go into system menu and try increasing buffer space - sometimes the error message actually gives you this option - but that's not always the cure. Other than that, either (1) avoid large files

or look on the web for a more complete explaination.
Sorry I can't help more.