Very strange. All was well till I put the latest Windows updates on last night. The first time today that I tried to specify a name for exporting a sequence, I got a serious error that terminated PP. I got a transient Windows message that said Premiere had broken some rule and would be put in some restricted mode. (I should have written it down but didn't.) PP still runs but when I bring up "File...Export...Media" and click on the "Output name" field I get a "Save As" box with nothing in it but Save and Cancel. No way to navigate to a folder or pick a name. This happens with all projects in PP CC 2014, all exported fine yesterday. It does not happen with PP CC.
I've got an up to date copy of Windows 7 Professional with plenty of everything in terms of hardware.