Why does WordPress say there has been an error cropping your image?

The upload worked but the server failed to cut and save the cropped copy. The usual causes are no image tool on the server (GD or Imagick), a picture too large for the memory available, a file type the server cannot edit such as HEIC or WebP, or a security plugin blocking the request.

How do I fix the logo crop error in the WordPress Customizer?

Crop the logo to the size the Customizer asks for on your computer, upload it, and click Skip Cropping. To fix cropping itself, check Tools, Site Health, Info, Media Handling and ask the host to enable the PHP GD or Imagick extension if no editor is active.

Does a big photo cause the cropping error?

Often. Phone photos of 12 megapixels or more can run PHP out of memory while cropping. Shrink the image to about 2000 pixels on the long side, or ask the host to raise the PHP memory limit to 256M.

More fixes

WordPress: "There has been an error cropping your image"

You pick a logo or header image in the Customizer (or a site icon under Settings), drag the crop box, click Crop Image, and WordPress answers "There has been an error cropping your image." The upload itself worked; the server failed when it tried to cut and save the new copy. Usually the server has no image tool switched on, the picture is too big for the memory it has, or the file type is one the server cannot edit. Here is how to tell which in a few minutes.

What the owner sees

harborbakery.example/wp-admin/customize.php

What the checks found

Which problem is it? (five minutes)

Try Skip Cropping. The same screen has a Skip Cropping button. If that works, your site is fine and only the editing step fails. If even an image that is already the right size fails, read on.
Check the image tool. Go to Tools, Site Health, Info, Media Handling. "Active editor" should say WP_Image_Editor_Imagick or WP_Image_Editor_GD. If it is empty, or "GD version" and "Imagick version" both say not available, the server has no way to edit images, and that is the whole problem.
Check the size of the picture. A phone photo of 4000 by 3000 pixels or more, or a file over a few MB, can run the server out of memory mid-crop. Shrink it to about 2000 pixels on the long side and try again. If the small copy crops, memory was the cause.
Check the file type. iPhone HEIC files, and WebP or AVIF on older servers, upload but cannot be edited. Save the image as a PNG or JPG (Preview on a Mac, Photos or Paint on Windows) and upload that.
Check for a security block. If small JPGs fail too and the image tool is present, open your browser's developer tools (F12), Network tab, and crop again. A 403 on admin-ajax.php means a security plugin or the host's firewall blocked the crop request.

Fix it, safest first

Upload a picture already the right size and use Skip Cropping. The Customizer tells you the size it wants (for example 250 by 250 for a logo, 512 by 512 for a site icon). Crop it on your computer first. This is the quickest fix and needs no server change.
Switch on an image tool. In cPanel, Select PHP Version, Extensions, tick gd or imagick and save. On other hosts, ask support: "please enable the PHP GD or Imagick extension". Then check Site Health again.
Give WordPress more memory. If only big images fail, ask the host to raise the PHP memory limit to 256M, or add define( 'WP_MEMORY_LIMIT', '256M' ); to wp-config.php above the "stop editing" line, after a backup.
Convert the file to PNG (logos, anything with transparency) or JPG (photos) when it was HEIC, WebP or AVIF.
Check the uploads folder can be written. If the crop fails and Media Library shows a blank thumbnail for the new upload, the server could not save the cropped copy. The upload errors guide covers folder permissions.
Security plugin block: look in the plugin's firewall log for the blocked admin-ajax.php request and allow it, or pause the firewall for the minute it takes to crop, then switch it back on.

What you see, what it means, what it needs

What you see	What it means	Usual fix
Every crop fails, Site Health shows no active editor	No GD or Imagick on the server	Enable the PHP gd or imagick extension
Small images crop, phone photos fail	Server runs out of memory on big images	Shrink the image, or raise the memory limit
Only HEIC, WebP or AVIF files fail	Server cannot edit that format	Save as PNG or JPG first
403 on admin-ajax.php in the Network tab	Security plugin or firewall blocked the crop	Allow the request, or pause the firewall briefly
Crop fails and the new upload has no thumbnail	Uploads folder cannot be written	Fix folder permissions (host or File Manager)

What not to do

Do not set the uploads folder to 777 to make it work. It lets anyone on a shared server write there.
Do not install several "image fixer" plugins at once; one bad one can break every upload. Fix the server tool instead.
Do not keep re-uploading the same huge photo; each try leaves another copy in the Media Library.

Most cases are a smaller picture with Skip Cropping, or the host switching on GD. If the host is not helping, that is what the box below is for. Related: upload errors, site icon (favicon), memory exhausted.