Thank you for your post!
I would recommend starting here:
1. Uninstall FileMaker Server 15.0.1
2. Rename the FileMaker Server Folder (for example: "FileMaker Server OLD")
3. Reboot the machine
4. Install FileMaker Server 15.0.2 (you can get this from your Electronic Software Download Page)
Verify you are following the recommendations in the Getting Started Guide.
If the issue persists with the new installation I can get some further information from you.