We also need to set correct permissions for storage files in the server. So, we need to give a
write permission in the storage directory as follows:
$ chmod –R 777 /var/laravel/app/storage
The preceding command will change the storage directories permission to
777 recursively, so all files and directories will be writable for Laravel. Also, you will need to set a permission for any of your image upload folders in the public directory in the same way.
If your host doesn't allow permissions via command line, then you can use your web admin panel's file manager to change permissions.