Several users have reported two problems since their Mac was updated to Mavericks (10.9). By following a few simple instructions, your issue will quickly be resolved.
Warning: You must have administrator access to proceed with these changes.
It's not possible to install a program that didn't come from the App Store
Go to "System Preferences" and then "Security and Privacy".
Authorise applications downloaded from "Mac App Store and Identified Developers".
Lag and disconnections with multiaccounts
Click on the "DOFUS" icon in the "Applications" folder, then "Get Info...".
Toggle the option "Prevent App Nap".