stuck with restart setup error

I removed distribution, stack and dns record manually then tried to use the plugin again but am stuck here without the ability to create new distribution:

There was an error deleting the stack. Try again.
The following response was returned:
Caught exception in method AmazonAI_Cloudformation::delete_cloudformation in class AmazonAI_Cloudformation:
Found 1 error while validating the input provided for the DeleteStack operation: [StackName] must be a string or an object that implements __toString(). Found bool(false)