When I try to do a mobile spy it always says that “Failed to execute runnable (org.eclipse.core.runtime.AssertionFailedException: null argument:)” what should I do?

You should share some more details. >:)

* o:)

Sorry, what I ask before is incorrect. What I want to ask is that I tried to spy the mobile app from my device, but it can’t capture any objects and always display an error message “Unable to start application on this device.: Fail to start Appium server in 60 seconds” what should I do?