Selecting any label in Space Categories leads to Page not found error

The link generated by selecting one of a item in Space Categories on the dashboard of Confluence creates invalid URL, leading it to "Page not found" error.

URL by clicking Space Categories, then select one of the labels:
http://confluence/dashboard.actionupdatesSelectedTab=team&updatesSelectedTeam=BLAH

The working URL after adding the missing '?' in the link above:
http://confluence/dashboard.action?updatesSelectedTab=team&updatesSelectedTeam=BLAH

Detailed steps:

1. Goto dashboard of Confluence.
2. Click Space Categories.
3. Select any available label.