I had the same trouble, and I reported the problem to Swagbucks. Here's the reply I received pretty quickly:
We understand that some members have had limited or no access to engage in video viewing on Swagbucks or nCrave sites in recent days. This is due to our use of an industry-standard third-party traffic verification service, which apparently may be having some issues with their systems incorrectly blocking certain users from this activity.
Please be assured that we would like to resolve this issue ASAP and are reaching out to the traffic verification service to see if anything can be done to alleviate this problem for the affected members. As we make progress on this issue, we will try to keep you informed, and apologize for any inconvenience some members may be experiencing from this technical issue in the meantime.
For all crediting issues, we will report it to the team in charge for review. We do apologize for the inconvenience and appreciate your patience.
Yesterday nCraves worked part of the day, then they disappeared. Today they have worked perfectly so far. At least we know they are aware there is a problem and are trying to address it.
Thanks for letting us know that they know! My nCraves worked perfectly yesterday. Today my nCrave page is blank and even the Daily Crave and nGage doesn't work. My earnings are going to be way down!