Run Magento 2.3.0 on PHP 7.1
I'm trying to upload a picture for
Contents> Design: Configuration> Transaction Emails> Logo Image
And get the following error.
A technical problem with the server has caused an error. Try it again
keep doing what you did If the problem persists, try again
I used this update to transfer the header and favicon image. However, it does not work for the above problem.