"The current transaction exceeded its quota limitations"


I just realized that Memex had stopped saving my history a month ago. The thing is, I was not aware of that. A message or a visual notification on the toolbar icon would have been greatly appreciated.

So when I try to star, highlight, add notes, tags or save page to a category… nothing works. Instead, I get the error message below:

ERROR: The current transaction exceeded its quota limitations.

I am using Memex’s extension on Firefox, so I suspect this could be due to the 2GB limit on Firefox. But I could not find any clear mention of that and, most importantly, how to remedy.