Symptoms

In every dashboard from JIRA the drop down menus are shown under the gadgets.

Cause

The look and feel configuration for Gadget Colour has hexadecimal values with less than 6 digits (i.e #3b73a). There is already a bug being tracked here: JRASERVER-38065 - Drop down menus are appearing under dashboard gadgets

Resolution

1. Go to Administration > System > User Interface > Look and Feel.
2. Check the Gadget Colours if there is a colour having a hexadecimal values with less than 6 digits.
3. If there is one, change it to use a 6 digit value (i.e #3b73af).