Whoops, looks like something went wrong in laravel 5.8

I have application developed in Laravel 5.8.
And I get this message Whoops, looks like something went wrong.

If the form content is just : input and image,then no problem.
If the form content has input, image and textarea, then I get this message
Whoops, looks like something went wrong
I try to set APP_DEBUG = True and clear cache, but the errors are still not visible.
And i don't have any element in LOG.

Anyone help me, because this project is in production.

via Chebli Mohamed