Intervention / Image Upload Error {{ Image source not readable }}

This is not to answer the OP's question, but to answer someone else's who is here with the same question with a different context.

If you are using File System method like storeAs() then you are actually uploading your file under /storage/app/public/ from /public/ scope. If so, you will need to run the following command:

php artisan storage:link

This command will create a shortcut link to the /storage directory under /public directory, and things should work normal.

Add the following parameter in your form tag:

enctype="multipart/form-data"

And change for this in make:

$img = Image::make($request->file('photo')->getRealPath());