Q: Is anyone have a problem with share function in FCP?

Try selecting "This computer" and see what happens.

Where it says Cluster>other, can you not select "this computer?"   If not, you have a seriously malfunctioning compressor.  Suggest you get digital rebellions compressor repair.  It's free.

A little research turns up this thread:

Try this:

Go to System Preferences and select Sharing. A box appears with your computer's name at the top and a list of things you can share. Select File Sharing and to the right, it will say something like: FTP Access:On with a message underneath which contains your computer's IP address e.g 10.6.4.3. Make a note of this number.

Open Compressor and go to Compressor > Preferences. The Preferences Dialogue Box appears and at the bottom it says: Enter IP addresses or ranges for manually selected computers. Click on the + button at bottom left and then enter your computer's name and the IP address you noted earlier. Online will probably appear under status.

Next time you start a job in Compressor and click on submit the drop down box will now say This computer in the Cluster box and the submit button will no longer be greyed out

Good find!

All right here's my last ditch effort:  Try the last two suggestions in this thread.   If those don't work I would uninstall and reinstall compressor and qmaster.  Then I would search these forums...this seems to have been an issue.