Best thing to do with errors in Linux is to google exactly what the error says and see what others have done to remedy the issue.
From: https://ubuntuforums.org/showthread.php?t=1366252&p=8570297#post8570297
"The problem is that when you downloaded the file, it didn't get saved with executable permissions (which is by-design)...
The somewhat cryptic message you get means that, since it's not allowed to run the executable file, it doesn't know how to open it.
Give it exe-permissions:
1. Right-click the file and choose Properties
2. Click on the Permissions-tab
3. Mark the "Allow executing file as program" and then close
4. Double-click the file again
"