Now it is working Rated 5 out of 5 stars

I was able to open the visio file sent to me by email in their website - for free. Thank you !

This review is for a previous version of the add-on (1.0.1-signed.1-signed). 

Big lie - It does not do what it says Rated 1 out of 5 stars

This add-on does not do what it says. I have even restarted my computer and no, no success. I even registered for free, and what they show you online is a very nice program to make diagrams like visio, but it wont let you anyway to upload a .vsd file to preview it with this viewer. This is a big lie, my friends.

This review is for a previous version of the add-on (initial.rev18.1-signed.1-signed). 

Updated Extension

Hi Wilfre_2013,

Thank you for your review! As you probably noticed, our Free Visio Viewer is brand new, so we appreciate your feedback and want to thank you for letting us know this wasn't working.

We just released an update that will take care of this for you. If you install the latest version, you'll be able to view Visio files without restarting Firefox.

Thank you again for your help. If you have any other questions, please feel free to contact us directly at support@lucidchart.com and we'll be happy to help. :)