The mount SD option is grayed out. I talked with HTC support for a bit. She had me go through the usual suspects and was stumped when nothing worked. She was saying for a while that even without a MicroSD, it should still connect to my PC.
A little while later she put me on hold to talk with somebody. When she came back she was telling me that the reason why it doesn't work is because I need an SD in there. I asked her if that was introduced in the new update but she said it's always been that way.
I wanted to ask her why she was so confident that I didn't need one before, but I wasn't getting anywhere at that point. I guess it's time to find a cheap SD card then.