Block Template won't load or cancel

I tried to add a block template to my course. It just keeps spinning and saying "inserting template". I tried to add it again and it worked fine but I can't get rid of the fist one, it's still spinning. There is no delete box on the right, the cancel button is not working, I closed Rise and reopened it, I restarted by computer. What can I do to get rid of this block that won't load? 

Thanks
Rosemary