I'm running PHP 7.2 and Magento 2.3 with a custom theme and when editing pages or creating new ones, when I try to add an image from the add image button I get this error:
A technical problem with the server created an error. Try again to continue what you were doing. If the problem persists, try again later.
Also, I cannot see any of the images from the left hand browser tab and also when I create a new folder, Never creates one.
I checked the log and there is nothing registered regarding this issue. And the only error that gets logged is not even related!
[2020-06-08 09:58:01] main.ERROR: Unable to resolve the source file for 'adminhtml/Magento/backend/en_US/Toogas_Easypay/fonts/toogas-icon.woff2'   [2020-06-08 09:58:01] main.CRITICAL: Unable to resolve the source file for 'adminhtml/Magento/backend/en_US/Toogas_Easypay/fonts/toogas-icon.woff2'  
I saw many people had a similar problem when they were trying to upload their logo.
But those solution didn’t work for me.
Solved! Go to Solution.
kindly refer below URL to :
This should be help to resolve this issue.
If issue resolve, please click on 'Kudos' & Accept as Solution!
Thank you for your help. I did all the steps mentioned in the link but it didn't fix the error.
OK After I enabled Error display functionality in my PHP.ini I see this error now:
Fatal error: Uncaught Error: Call to undefined function mime_content_type() in /home/..../public_html/vendor/magento/module-cms/Model/Wysiwyg/Images/Storage.php:362 Stack trace: #0 /home/..../public_html/generated/code/Magento/Cms/Model/Wysiwyg/Images/Storage/Interceptor.php(37): Magento\Cms\Model\Wysiwyg\Images\Storage->getFilesCollection('/home/...', 'image') #1 /home/...../public_html/vendor/magento/module-cms/Block/Adminhtml/Wysiwyg/Images/Content/Files.php(60): Magento\Cms\Model\Wysiwyg\Images\Storage\Interceptor->getFilesCollection('/home/.....', 'image') #2 /home/..../public_html/vendor/magento/module-cms/Block/Adminhtml/Wysiwyg/Images/Content/Files.php(74): Magento\Cms\Block\Adminhtml\Wysiwyg\Images\Content\Files->getFiles() #3 /home/..../public_html/vendor/magento/module-cms/view/adminhtml/templates/browser/content/files.phtml(13): Magento\Cms\Block\Adminhtml\Wysiwyg\Images\Content\Files->getFilesCount() #4 /home/...../public_html/vendor/magento/framework/View/Tem in /home/...../public_html/vendor/magento/module-cms/Model/Wysiwyg/Images/Storage.php on line 362