I have the exact same problem described in this thread,
Clearing of cookies and the other methods described within the thread have not worked. I am running Windows 10 build 1803 and the problem just showed up today. I also use Firefox and AdBlock Plus with no issues. I submitted this bug to Microsoft in the Feedback Hub for Windows 10 and also mentioned it on AdBlock Plus' Twitter Page. Uninstalling and reinstalling of the extension did not help. This is the first problem that I have with this plug in, and have been very happy with ABP, until this issue.
Satch