I tried to upgrade MongoDB from 3.7.3 to 3.7.5 on Windows 10 Ultimate. Since libeay32.dll and ssleay32.dll are not provided in the new ZIP file, I copied them from the 3.7.3 distribution ZIP. I used the same config and also the same PEM file as before. However, I'm getting the following error message in the logfile:

2018-04-24T08:17:13.302+0200 F CONTROL [main] Failed global initialization: InvalidSSLConfiguration: Expected to find 'RSA PRIVATE KEY' in PEM file, found 'PRIVATE KEY' instead.