Multisite error when creating a new site

I’m using 3.5 R6. I have multisite installed in a subdirectory on ssl. When I add a new site to my network, I get an error that says, “Are you sure you want to do this?”

My home site is in a path like:

https://ue.domain.com/acme/

The new site I’m trying to add would be at

https://ue.domain.com/acme/newsite

I thought 3.5 allowed multisite to install in subdirectories like this. Is it not working, or is the problem due to my path (that it’s ssl, and also combines a subdomain in there)?

Tom