Laravel The Response content must be a string or object implementing __toString()?

Question

Laravel

Errors are pouring in:
exception 'UnexpectedValueException' with message 'The Response content must be a string or object implementing __toString(), "boolean" given.' in /var/www/dev/vendor/symfony/http-foundation/Response.php:397
Cause - debugbar (requests go to /_debugbar/open)
How to find the cause?

Answer 1

is there a call stack? It is necessary to look in it why there is a boolean, and not a string.
So no one will say.