User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:36.0) Gecko/20100101 Firefox/36.0 Build ID: 20150320202338 Steps to reproduce: Set the wav file to open with firefox as default. Double clicked the file. Actual results: Firefox started opening many empty new tabs Expected results: played the wav file natively (without quicktime hopefully?)

Hi Reporter, I have tested your issue on latest Firefox release (43.0.1) and latest Nightly (46.0a1) and I could not reproduce it. I set the wav file to open with Firefox as default, after I opened the file Firefox started with one tab. To play the wav file you must activate QuickTime. Firefox: 46.0a1, Build ID: 20151221114259, User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:46.0) Gecko/20100101 Firefox/46.0 Firefox: 43.0.1, Build ID: 20151216175450, User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:43.0) Gecko/20100101 Firefox/43.0 Can you please test this on the latest Firefox release (43.0.1) or latest Nightly (46.0a1, https://nightly.mozilla.org/) and tell me if this still reproduces for you ? When doing this please use a new fresh Firefox profile. Thanks, Cosmin.