I installed BBManager to my Mac and I get above error message when opened for the first time?
Hi, Mak2Pak. Try this: control-click on the BBM icon and click Open.
And if that doesn’t work (although it should), you can make a temporary change to Gatekeeper. Just don’t forget to change the setting back to what it was before you changed it: <https://support.apple.com/en-us/HT202491>
The first time you try to open up the BBManager it may give that error message. There should be an option to open it anyway, as @persist pointed out. Let us know if you still experience issues with this. We’ll be more than glad to assist you further.