User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:54.0) Gecko/20100101 Firefox/54.0 Build ID: 20170608105825 Steps to reproduce: go to paypal try to print postage when you click to print the postage it goes into an infinite loop opening new tabs with a url to the local disk drive (no such file exists) Also had same result trying to print a 1099 pdf from E-trade financial Actual results: firefox goes into infinite loop opening new tabs, presumably with the pdf but the url is to the local hard drive and the file is not there. Expected results: click on the pdf link and the pdf opens in a new tab. this used to work fine until about a week ago. Works fine in Chrome

User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:54.0) Gecko/20100101 Firefox/54.0 I had tested this issue on Windows 7 and 10 x64 with latest Firefox Release(54.0) and the latest Nightly (56.0a1-20170608105825) and haven't managed to reproduce it. After login in to paypal and clicking to print a postage, a new tab is opened with the printing details and also the "Print" option window is displayed. I haven't encountered any hangs or loops during this process. Can you please re-test this with a new clean Firefox profile, maybe even safe mode, to eliminate custom settings as a possible cause (https://goo.gl/AR5o9d). Thank you!

The issue does not occur until you actually print the postage. I get the new tab with the print option just fine. Now click the print button and you will have to close firefox to continue.

Here is an example from today. Went to https://www.carefreeazfestivals.com/williams-events.html click on Click here to download exhibitor application. Firefox tries to open the following in a zillion new tabs. file:///C:/Users/Marsha/AppData/Local/Temp/8b5d2db860cf01cea3c513da978bacee.pdf as I have not downloaded the file yet it is not on my C: drive it is a pdf it should open in firefox from its location of https://nebula.wsimg.com/8b5d2db860cf01cea3c513da978bacee?AccessKeyId=860C592570B4E90D5CB5&disposition=0&alloworigin=1

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:56.0) Gecko/20100101 Firefox/56.0 I have re-tested this issue on Windows 7 x64 and Windows 10 x64, on the latest Firefox Release(54.0.1) and the latest Nightly(56.0a1-20170710030203) and haven't managed to reproduce it. When loading the URL specified in comment 3 and clicking on the "Click here to download exhibitor application", the following link is successfully loaded in the browser https://nebula.wsimg.com/63a946cd23e253468cb704328d88a246?AccessKeyId=860C592570B4E90D5CB5&disposition=0&alloworigin=1 Can you please re-test this with a new clean Firefox profile, as specified in comment 1? The issue might be due to your firefox preferences or installed add-ons, so by testing with a clean firefox profile its possible to check if this is responsible for the issue you are experiencing. Thank you.

Considering the fact that Emil could not reproduce this and the fact that the reporter did not answer his request until now, I will mark this as Resolved-Worksforme. If anyone can still reproduce it on latest versions, feel free to reopen the issue and provide more information.

(In reply to Ciprian Muresan [:cmuresan], Experiments QA, :steve from comment #5) > Considering the fact that Emil could not reproduce this and the fact that > the reporter did not answer his request until now, I will mark this as > Resolved-Worksforme. > > If anyone can still reproduce it on latest versions, feel free to reopen the > issue and provide more information. I have this issue on 60.0.2 under Ubuntu. Attempting to open any pdf file will result in an infinite loop of new tabs being opened. They are all blank, and the address refers to the file location where the PDF document was downloaded to. The entire browser then needs to be closed. In some cases, the browser will open up on its own again, and may need to be closed multiple times to end the loop.