Hey @leobmaan!
My biggest suggestion is to let it ride. Give it about 30 minutes or so at that number before restarting it. It’s likely installing a large file, and the progress isn’t increasing because of that, once that file installs it will continue. But I haven’t seen any 5.2.0 installation issues around. You’ll likely run into the same thing the first time you launch the engine, as well. It’s because these installation bars run on # of files, not % of data 
Now if that doesn’t work, please come back and reiterate.
OH and make sure you have about double the size of the installation available on your hard drive for pagefile usage during installation!