Hi acac12, what method are you using the save the file? In the image, it looks a bit like Video DownloadHelper. On their support forum, I see a few threads mentioning EPERM. Do any of these help:

eperm (in Video DownloadHelper Q&A) - Google Groups Search

Those threads don't relate to the specific error message I am getting. This error message prevents any downloads using video downloadhelper.

I removed both firefox and video downloadhelper and reinstalled but the problem remained, hence my post here.

Does the problem occur when you are not using Video DownloadHelper, or is the problem only using the add-on?

Hello acac12,

Maybe you could check to see if you have granted permission to access certain folders :

https://nektony.com/duplicate-finder-free/folders-permission

Also (even though this works on Mojave), maybe this might work for you :

http://osxdaily.com/2018/10/09/fix-operation-not-permitted-terminal-error-macos/

(edit typo)

McCoy said

Hello acac12, Maybe you could check to see if you have granted permission to access to certain folders : https://nektony.com/duplicate-finder-free/folders-permission Also (even though this works on Mojave), maybe this might work for you : http://osxdaily.com/2018/10/09/fix-operation-not-permitted-terminal-error-macos/ (edit typo)

Changing the permission for Firefox in the Privacy tab resolved the problem.

Thank you very much.

Hi McCoy, which settings did you change on your permissions on Firefox for the downloads to work. I have the same EPERM error and i have Firefox version 71.0 .

sudhir.r said

Hi McCoy, which settings did you change on your permissions on Firefox for the downloads to work. I have the same EPERM error and i have Firefox version 71.0 .

Hello sudhir.r,

I didn't, as I never needed to ....

Two things I'd like to suggest :

1. Please update Firefox to the latest version (75.0).
2. Maybe start your own thread, using this link :

https://support.mozilla.org/en-US/questions/new/desktop/other

(you'll have to scroll down to the bottom of the page)