User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:58.0) Gecko/20100101 Firefox/58.0 Build ID: 20171009220104 Steps to reproduce: On Firefox Nightly, 58.0a1 (2017-10-09) (64-bit) visit https://www.brain.fm/app#!/register Actual results: Website hangs on loading interstitial. dev console errors: XML Parsing Error: junk after document element Location: https://www.brain.fm/app/html/templates?v=1.79978 Line Number 1, Column 244: templates:1:244 TypeError: g.flags is undefined [Learn More] bwfm2.min.js:8:3737 NS_ERROR_UNEXPECTED: Expected results: started playing music after a short while. I checked that the site worked as is in Google Chrome. no errors in dev console. i believe this is a regression - worked a couple days ago.

Tested using latest Nightly Version 58.0a1 2017-10-13 Build ID 20171012220111 Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:58.0) Gecko/20100101 Firefox/58.0 and and reproduce the issue. Also I can confirm that this is a regression (works just fine using Nightly 58.0a1 (2017-10-06) (64-bit) build). Similar issue 1406785 (also a regression around that date) - which may be related with this bug. gabe.saravia Thank you for reporting it.

There's no CSS in this test.

Would you please run mozgression tool to help get the regression window, Deac Alin?

(In reply to Jet Villegas (:jet) from comment #2) > There's no CSS in this test. Yes, you are right, at the moment it seemed the right component(my bad). (In reply to Hsin-Yi Tsai [:hsinyi] from comment #3) > Would you please run mozgression tool to help get the regression window, > Deac Alin? Mozregression for this issue: Last good revision: 1053bf2fbaed195d37a07ae81d5086cac0b8f6b8 First bad revision: 224d8c57a4693138c8823ac108659bb1fe5b308e Pushlog: https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=1053bf2fbaed195d37a07ae81d5086cac0b8f6b8&tochange=224d8c57a4693138c8823ac108659bb1fe5b308e Looks like the following bug has the changes which introduced the regression: https://bugzilla.mozilla.org/show_bug.cgi?id=1405571

(In reply to Deac Alin from comment #4) > (In reply to Jet Villegas (:jet) from comment #2) > > There's no CSS in this test. > Yes, you are right, at the moment it seemed the right component(my bad). > > (In reply to Hsin-Yi Tsai [:hsinyi] from comment #3) > > Would you please run mozgression tool to help get the regression window, > > Deac Alin? > > Mozregression for this issue: > Last good revision: 1053bf2fbaed195d37a07ae81d5086cac0b8f6b8 > First bad revision: 224d8c57a4693138c8823ac108659bb1fe5b308e > Pushlog: > https://hg.mozilla.org/integration/autoland/ > pushloghtml?fromchange=1053bf2fbaed195d37a07ae81d5086cac0b8f6b8&tochange=224d > 8c57a4693138c8823ac108659bb1fe5b308e > > Looks like the following bug has the changes which introduced the regression: > https://bugzilla.mozilla.org/show_bug.cgi?id=1405571 Thanks Deac! I see so errors on the latest nightly. As bug 1405571 was backed out, could you verify if it's fixed already?

Tested on latest Nightly 58.0a1 ID: 20171015220106 and the issue is no longer reproducible. Thank you