I tried deleting several tags with possibly the same name, but it didn't work. I deleted the entire BrowserAssist and reinstalled it to solve the problem. I also backed up the files, but I'm not sure if there's a better way.
An unexpected error occured during BrowserAssist startup relating to loading of the BA stored meta data (e.g. Tags etc). To preserve the integrity of that data, BrowserAssist will not operate until the issue is resolved. Previous backups can be restored from the Plugin UI to resolve this issue...