I guess something went wrong in Pushing the package of Smart View in your environment . Check with your IT Infrastructure team , and get them re installed and Pushed again explaining the inconvenience.
Is the installation done with local admin account?
Whenever I encounter this issue, I simply close that excel, end all the processes relating to excel and reopens excel.
However said that, this is known issue and we have a unpublished bug for the same EXCEL HANGS WHEN OPENING OR SAVING A FILE[Bug ID 12957863] (Sept 8, 2011).
you can refer following GlennS's blog for more info as well.