Thank you for your post.
Using FileMaker Server 14.0.3 on Mac OS X 10.10.5, I can launch Safari 8.0.8 from another Mac OS X 10.10.5 machine and access a database file. I used the default custom web page that comes with FileMaker Server (fmwebd_home.html). I entered:
http://<IP Address of server>/fmi/webd?homeurl=<IP Address of server>/fmwebd_home.html#FMServer_Sample.fmp12
The FMServer_Sample file opens fine, and when I log out, the custom home page is then displayed.
If you don't use the file extension, FileMaker WebDirect will assume the extension is .fmp12.
Make sure your filename does not include a period, as this would be interpreted as a file extension.
Let me know what I'm doing differently than you so I can replicate the issue.
Thanks for the reply.
I’ve checked this again today and my experience is the same as yours now.
Since reporting this, I’ve changed from a DNS entry to a redirect to find the HTML page that opens the FileMaker file. The service provider’s DNS settings just wouldn’t work reliably and they couldn’t fix it, so maybe this upset Safari. Perhaps the change to a redirect, or umpteen Safari cache dumps, or both fixed the problem I reported.