Extension failed

@ayemanservicesbd - I can't see from your screenshot, BUT if the error says something about the extensions folder, most likely that folder is missing, so just create it at the right location you see in the error message and chmod it to 0777.
This happens when you unzip the MailWizz archive in your Control Panel, for some reason, it misses the extensions folder, which is there in the archive. And the solution is to create it manually.