Unable to download, save and verify the package. Check your internet connection.

I don't know if anyone will be able to answer this question. It's regarding the extensions in resource manager such as the drumline extension. Whenever I try downloading any extension, it stops at about 56% and this message pops up:
"Unable to download, save and verify the package. Check your internet connection." I know my internet connection is not the problem. I've tried many workarounds such as downloading the separate files for the extensions and dropping them in muse score. The problem with that is I then have to update the extension which gives the same warning message. If I don't update it, I can use the drumline extension but there is no sound and I'm missing some options in it. I've tried changing the folder location in preferences and that didn't work. I've even used the factory reset option about 5-10 times. I've spent about 12 hours searching for a solution and have had no success. If anyone could help, it would be very much appreciated.