This particular key probably won't cause a problem but if it does feel free to reach out once again. However, it is due to some security/firewall feature enabled on your machine that is most likely the culprit.

After re-install I received an installation error:

Regarding this particular error this it may indicate a permission/firewall problem. I'd suggest rebooting first and trying the installation again otherwise make sure you have admin privileges and/or any firewall settings aren't blocking this.

So at the end I got it working. I removed all 11.x versions an deleted the wolfram and mathematica directories in the C:\Users\lvveen\AppData\Roaming directory.

After re-install I received an installation error:

I decided to ignore it and move on..

I went to the ImageRestyle documentation and started the example Then it started to reload the GPU libraries

After this a restart was asked:

After the restart back on the page and a download was started again (this did not happen with previous installs)

Now it works for ImageRestyle:

and also for NetTrain:

I'm still a bit worried about the install error message but it seems to have no effect. Would love to hear if this is indeed save to ignore or not.