Configuring SSL in Content Server gives Error 13

Hi there,

I'm using Let's Encrypt and get Error 13 when I configure the paths to certificate and key files in Preferences -> Sharing over the net -> Advanced.

If I remove the paths (i.e. no SSL) then the Content Server (CS) starts as it should.

What am I missing?

My temporary solution is to run the CS via a simple script (i.e. bat file) which ask for Administrator priviliges to start the server.

Cheers!

P.S.: I looked in vain for a log but there doesn't seem to be any (e.g. calibre.log, *.log)