** Please try the below suggested workaround first in version 2.0 or 2.1. You also have the option of upgrading to our latest DSM version 4.0 (BETA) that resolves the problem through a patch**
First, delete the 'SpaceClaim' folder located at C:\Users\"Your Username"\AppData\Local\SpaceClaim and launch DS Mechanical again.
Then, head into File -> DesignSpark options -> Appearance.
Change the ribbon style to 'Windows 8 (Office 2013)', click OK and then restart the DesignSpark Mechanical software.