A WebmasterWorld thread reported that AdWords Editor has been having issues connecting to AdWords since December 29th. The error people have been getting on and off was:
Adwords Editor was able to contact Adwords, but there was a problem with the communication. Please try again later.
AdWordsAdvisor came back to the forums from an extended new years vacation on January 7th. On January 8th the issue was finally resolved.
This morning we are able to access all accounts normally again and can get back to business.
There are several more confirmations in the thread that the error has been resolved, for now at least.
Forum discussion at WebmasterWorld.