Over the last few days, there have been a number of people who have reported that they can no longer start WatchMe. Each time they do they get the following message:

Can not start WatchMe
An instance of WatchMe is already running

The issue only occurs for people who run AVG Anti Virus and downloaded their latest update. I have submitted an issue to AVG explaining the situation, and hopefully they will be able to rectify the issue.

In the meantime, if you are getting this issue and run AVG Anti Virus, you can fix it by excluding WatchMe from AVG. Information on doing this can be found here:
https://support.avg.com/SupportArticleView?l=en_US&urlname=How-to-exclude-file-folder-or-website-from-AVG-scanning

Thank you to Mal, Max and Lou for letting me know about this issue.