There seems to be an incompatibility between the current version of the Gnome Shell in Fedora (*) and the following Gnome Extensions:
- Places Status Indicator
- Removable Drive Menu
So as a workaround you can switch these extensions off, at least until a real bugfix is provided by the Fedora team.
(*) More precisely, it's a problem in gjs package. As I just found out there is an updated package version available, but it hasn't even reached updates-testing yet. But you could give
dnf install https://kojipkgs.fedoraproject.org//packages/gjs/1.50.4/1.fc27/x86_64/gjs-1.50.4-1.fc27.x86_64.rpm
Addendum 2018-02-07: The fixed version of
gjs is now available as regular update, so simply updating Fedora should help.