Hongmeng running project shows error: failed to start ability. Error while Launching activity.

DevEco Stidio running the project with a local emulator shows:

error: failed to start ability. 
Error while Launching activity.

In fact, your project has been loaded into the emulator, but there is a problem with the emulator.

Solution:

1. Use the remote emulator to run and see
2. Reinstall the local emulator

I don't know exactly what caused it, but reinstalling solved it.
If there are other solutions that do not require reinstallation, please let me know.