Craft 3 RC is installed locally. After clicking on the Plugin Store the loading animation stays for 1-3 seconds. After that, the right canvas leaves grey without content.

• I've checked the XHR request, it seems working.
• reinstalled Craft with composer
• tested several browsers

What could be a reason for an empty Plugin Store?

Update

I've tested the issue with a clean install of Craft 3, same problem there. So it should be something global on my machine.

Someone have an idea where the problem could be hidden?