Symptoms

• Unable to use multiple monitors with Mac OS X client
• I am not able to move application to external display connected to Mac

Cause

Mac client doesn't support using multiple Desktops, however, it supports spanning desktops/apps across all monitors. In OS 10.9 (Maverics) Apple has introduced Displays have separate Spaces feature that prevents OS X apps from spanning across desktops. For additional information, please refer to this article.

Resolution

Disable Displays have separate Spaces feature on the Mac and configure Parallels RDP client:

• go to System Preferences > Mission Control > uncheck "Displays have separate Spaces":

  

  NOTE: To apply this set log out from Mac and log in back.

• In Parallels RDP Client Connection Properties switch to Displays tab > uncheck User primary monitor only and check Span desktops across all monitors: