Thank you for your interest in OpenShot Video Editor. I'm happy to help you to resolve your issue.  In macOS, if you receive an error message that states: 

"OpenShot Video Editor can’t be opened because Apple cannot check it for malicious software."
"This software needs to be updated.  Contact the developer for more information." 

You can correct this issue.  Apple macOS needs permission to run the file that you downloaded from the Internet.  There are a couple of methods that may work.  Please try the procedures below (in order) to see if one of them works for you.
  1. Go to System Preferences > Security & Privacy > General > Click the lock in the bottom left corner > Enter your password > Click Unlock > Click Open anyway near the bottom > Open.
  2. Go to System Preferences > Security & Privacy > General.  You might see one or more alerts near the bottom that say something like, "OpenShot is an application downloaded from the Internet.  Do you still want to open it?" Click "OK" or "Yes" or whatever is the affirmative option on all of them.  Also, ensure that you select the "App Store and identified developers" radio button on the same tab.
If you have any additional questions or concerns, please let me know.