Firefox Extension "Add on Corrupt" popup

[Reg]

When I attempt to Install the extension into Firefox 56.0.1 a popup appears saying "This add-on could not be installed because it appears to be corrupt".

What can I do to download the extension and get it to work with/in to Firefox?

[Peter]

Hi,
you can install the extension from the Firefox store https://addons.mozilla.org/en-US/firefox/addon/downloadstudio-firefox-integra/. We have submitted an updated extension to support the latest Firefox 64-bit version but it has not yet been approved so the current extension will only work with Firefox versions prior to 56.0

[Peter]

The addon has now been approved.
You will need to get an updated version of the fxwrap dll file from http://www.conceiva.com/downloads/STempFiles/FxWrap.zip

Extract the contents of the zip file to the folder where you installed DownloadStudio, 1 file will be overwritten. The updated addon is available from https://addons.mozilla.org/en-US/firefox/addon/downloadstudio-firefox-integra/, the version number is 10.3.