I just have been unable to add a site logo. When I click to add one, I get taken to the dialog to choose a logo image, when I choose one, I get a blank ‘Crop Image’ dialog with no image displayed to crop and no errors displayed at all.
The logo image size I have is 747x250px, and I have assumed that it will be auto-scaled down to fit. Setting Logo Width to to any value, even the max 800px makes no difference.
I enabled WP_DEBUG, but no errors are displayed when this is happening.
Even at reduced logo sizes, I struggled with this. Also, even uploading an image in that dialog became problematic and will just freeze and not offer the upload drop area … once it did offer the upload drop area, but then froze when I began to upload a file and never completed the upload.
All of these with no errors displayed anywhere and debug enabled …
So, I reasoned that it may have some conflict with media related plugins, so I disabled the 2 media related plugins I have … Enhanced Media Library and Media Library Assistant.
Eventually I was able to get round this problem … but I cannot say conclusively if this was a conflict with either media plugin and I just don’t have the time to troubleshoot it.