There are incompatibility issues with Mac OS 10.7 , 10.8 , 10.9, 10.10 Yosemite and LabPrints. Please follow the following steps as applicable:
Mac "Gatekeeper" prevents LabPrints from being installed on some machines. You will notice the error message that the "application is damaged" . If you are not seeing this error message, then skip this step. To fix this problem please watch this video, or follow these steps:
From there you can set to "anywhere" to install LabPrints on Mountain Lion.
UPDATED MAC INSTALLERS:
NOTE: If you already have an old version of Production Studio on your mac, you must remove the Production Studio v5 folder from Applications/LabPrints/Production Studio v5 before installing.
NOTE: You may need to create a NEW test project with your OLD lab to have your old projects show up if upgrading to Lion or Mountain Lion.