Unfortunately, the very first step in our troubleshooter is the issue of
 using the correct browser.  Roll20 only supports latest-release 
non-beta editions of Firefox and Chrome.  While Roll20  will  work in a variety of browsers, in order to maximize 
your playing experience and take advantage of everything that Roll20 can
 do, you should use the latest version of either  Google Chrome  or  Mozilla Firefox .  That
 said, if your player is willing to swap browsers and this issue 
continues to happen in the future, you could carefully work through the 
first three steps of our guide to  Solving Technical Issues .     Step 1: Make sure to use the right browser   Please check if these issues persist when using both Chrome  and  Firefox.     Step 2: Ensure that there are no extensions/addons interfering with Roll20   Please disable  all  add-ons/extensions  and  anti-virus programs.     Step 3: Clear your cache     If none of the above succeeds, please thoroughly work through  Step 4 .  (Don't forget the complete Console Log!)   Thank you!