Sorry, MindNode doesn't launch on your Mac!
Please try the following:
Should the issue persist please send us a detailed description of what's happening and also the following information:
In the Finder app, go to the Applications folder. Press control and click on MindNode. Now select Show package contents, go to the subfolder Contents/_MASReceipt and send us the receipt file.
Open the Terminal app from the Applications folder. Paste the following command and hit return: ifconfig en0 | grep ether | pbcopy
This copies your primary Mac address to the clipboard, you can now paste it into an email and send it to us.
With these two components, we can check if the problem has something to do with the technical AppStore receipt handling.