Thanks for posting! I am sorry your UGA-4KHDMI adapter stopped as expected and I would be happy to help.
Given your description of the behavior, our first step is to examine some log files from your system.
If you would, please keep the adapter connected to your system with the monitor attached (even though it is not working) and send the output of our diagnostic utility PlugDebug –> http://plugable.com/support/plugdebug to email@example.com with ‘For Ticket # 216244’ in the subject line. This will allow us to match things up and examine some log files from your system to help determine the next steps.
* Please also include in your email the Amazon Order ID number for the adapter purchase (available from Amazon.com/orders) *
** Please do not post either the PlugDebug or the Order ID number in our public forum, only include them in your direct email **