this error: emulator-5554 disconnected! Cancelling com.something activity launch'

Sometimes this error occurs:

emulator-5554 disconnected! Cancelling ... activit开发者_开发技巧y launch'!

Please tell me what to do.

I had also faced this problem in past and one of below solutions may solve your problem.

first solution

Open Android Virtual Device Manager select the AVD you use for your app. Press the start button and wait for a new form to show up called (Launch Options). Check the box "Wipe user data" and hit "Launch" button.

second solution

go to task manager and process
adb.exe 32* and end this process
then restart your eclipse. 

you have to reset your adb. go to Eclipse IDE-->window--> Show Views --> device--> view menu --> reset adb

In my case it seems that AVD file was corrupted. I just created new AVD and it worked.