Magento 2.3.0 "A technical problem with the server created an error." When uploading the logo image

Question

I'm using Magento 2.3.0, with php 7.2 version, on a ubuntu os. Everything looks working fine, but when I try to go into Magento backend, Content - Design/Configuration - Header, and I try to upload the logo image, I get this:

A technical problem with the server created an error. Try again to continue what you were doing. If the problem persists, try again later.

I have tried already to change the user password, to check the index.php for any echo code, tried also to upgrade, compile, deploy, reindex, clean cache, but nothing, I still get this error..

Answer 1

There is a bug in the Magento 2.3 version, but you can resolve the issue by making changes in the following code.

Navigate to the file located at: /vendor/magento/module-theme/view/adminhtml/ui_component/design_config_form.xml and replace the occurrence of "fileUploader" with "imageUploader" This adjustment will address the problem.

Please see below for more information.

    <collapsible>true</collapsible>
                <label translate="true">HTML Head</label>
            </settings>
            <!-- Remove this code -->
            <!-- <field name="head_shortcut_icon" formElement="fileUploader">-->
           
            <!-- Add this code -->
            <field name="head_shortcut_icon" formElement="imageUploader">
                <settings>
                    <notice translate="true">Not all browsers support all these formats!</notice>
                    <label translate="true">Favicon Icon</label>

                <collapsible>true</collapsible>
                <label translate="true">Header</label>
            </settings>
            <!-- Remove this code -->
            <!-- <field name="header_logo_src" formElement="fileUploader"> -->

            <!-- Add this code -->
            <field name="header_logo_src" formElement="imageUploader">
                <settings>
                    <label translate="true">Logo Image</label>
                    <componentType>imageUploader</componentType>

Please check and let me know in case of any issue.

Answer 2

This is a Magento 2.3 bug, added wrong value for formElement for field header_logo_src

You can go to the file vendor/magento/module-theme/view/adminhtml/ui_component/design_config_form.xml

and in line number 154 you can see <field name="header_logo_src" formElement="fileUploader"> this you can change with <field name="header_logo_src" formElement="imageUploader">

But editing Magento core is not a good idea, for temporary fix till Magento release the patch you can use the following module I created just to rewrite design_config_form.xml

https://github.com/arshadpkm/magento-2.3-header-logo-upload-bug-fix

Answer 3

Assign permission to them,

Please Follow this link: https://github.com/magento/magento2/issues/10071

Answer 4

This is a bug in Magento 2.3. It will be fixed in the upcoming 2.3.1 release. Please refer to this link: https://github.com/magento/magento2/issues/18688

Answer 5

The error message "A technical problem with the server created an error. Try again to continue what you were doing. If the problem persists, try again later." plus the popup "A problem occurred" on Magento 2 back-end is related to rewrite issues according to my logs and it was fixed by correctly configuring the server. If you run this on nginx server please check if you have the configuration file that comes with Magento default on the webroot/nginx.conf.sample is copied/renamed and included in your nginx configuration and has the below block:

location / {
    try_files $uri $uri/ /index.php$is_args$args;
}

Answer 6

You can also try to increase the memory_limit in your .htaccess file in magento folder.