As SessionBox is currently not in the Firefox addon library, we host the installation file for it. Therefore when installing, you will see a notification stating this. That's totally OK and should cause no problem at all, however, sometimes Firefox is unable to properly install this type of extensions. Here's what you need to do now:
Step 1: Access https://sessionbox.io/ on your Firefox browser.
Step 2: Right-click “Install for Free” or “Install” button and select “Inspect Element”.
Step 3: Navigate to the “Network” tab. Note that what is listed may not be relevant yet to downloading the FireFox addon.
Step 4: Now go ahead and left-click the button that you previously right-clicked while the “Network” tab is still open. There is NO need to click on “Allow” or “Don’t Allow” when prompted. Note that you now see different domain entries on the “Network” tab with “sessionbox.io” as the domain name instead of the previous “bootstrapcdn”.
Step 5: Left-click on the single entry. Note the “Headers” tab that appears on the right of the entry.
Step 6: Find the line with “Request URL:” (It’s the first line for me). That line shows the URL to download the plugin without needing to contact support to find it for you.
Step 7: Copy the URL just mentioned and open a different web browser.
Step 8: Paste and go to the copied link. This should prompt a manual download of the addon xpi file.
Step 9: You can now manually install SessionBox addon on FireFox addon by simply dragging and dropping the xpi file into the FireFox window.
Thanks to Ahmad Iskandar for the details on how he fixed this issue!
Please note that we are planning to set up a Downloads page, where you will spare the first 6 steps and get direct links to the current versions. Also, getting into the Firefox addon library is a plan for us, however the very long time needed for that is not really something that is suitable for a continuously updated and frequently released software and can lead to extension and backend API mismatch. Please contact us, if you see any other errors when installing