Mozilla released the Firefox 52 version of its browser on March 7, 2017. Firefox 52 drops NPAPI support, which may affect your use of the Aspera Connect plugin on Firefox.
Am I affected?
You are affected if you use Firefox 52 and can no longer use Connect as before. Your web application may tell you that Connect is not installed, even though it is, and transfers will no longer work.
If you are affected, the issue most likely has to do with your web application server, which your server administrators will need to upgrade. Send your server admin the following article for more information: Supporting Connect on your server after the Firefox 52 release
In the meantime, you can also use Safari or Internet Explorer, which are browsers that still support NPAPI and ActiveX respectively.
There are other workarounds you can employ if you want to continue using Firefox.
1. Enable NPAPI support in Firefox 52.
a. In your address bar, type the following and hit enter:
b. Click the I accept the risk! button
c. Right click anywhere in the table and select New > Boolean. Enter
plugin.load_flash_only as the preference name, then click OK.
d. Select false as the value, then click OK.
e. Restart your Firefox browser (close and reopen it)
2. Downgrade your Firefox to version 51 or earlier
Old installers for Firefox 51 can be found here: https://ftp.mozilla.org/pub/firefox/releases/51.0.1/