Unable to fetch a list of attachment IDs to process

Hmm, that’s really weird. It seems like you have missing or malformed metadata for one or more attachments. I’ll add some code to make it more robust and then release a small update.

Thanks for posting the errors by the way. They were extremely helpful. ??

Can you replace /wp-content/plugins/regenerate-thumbnails/includes/class-regeneratethumbnails-regenerator.php with this newer version to see if it fixes it?

https://raw.githubusercontent.com/Viper007Bond/regenerate-thumbnails/master/includes/class-regeneratethumbnails-regenerator.php

I think the code I added should avoid those PHP warnings but I need confirmation. ??

Looks the same or even worse(screen)

[17-Dec-2017 07:25:51 UTC] PHP Warning:  Illegal string offset 'sizes' in /............../wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php on line 342
[17-Dec-2017 07:25:51 UTC] PHP Recoverable fatal error:  Object of class stdClass could not be converted to string in /............../wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php on line 342
[17-Dec-2017 07:25:52 UTC] PHP Warning:  Illegal string offset 'sizes' in /............../wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php on line 342
[17-Dec-2017 07:25:52 UTC] PHP Recoverable fatal error:  Object of class stdClass could not be converted to string in /............../wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php on line 342
[17-Dec-2017 07:25:53 UTC] PHP Warning:  Illegal string offset 'sizes' in /............../wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php on line 342
[17-Dec-2017 07:25:53 UTC] PHP Recoverable fatal error:  Object of class stdClass could not be converted to string in /............../wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php on line 342

LINK

If You need some particular detail/info feel free to ask. I will try to help.

If this helps, I’m having similar issues. I just installed this plugin for the first time. Latest WP 4.9.1 is installed:

[18-Dec-2017 17:54:09 UTC] PHP Warning: Illegal string offset ‘sizes’ in /home2/lyltsklj/public_html/wp-content/plugins/regenerate-thumbnails/includes/class-regeneratethumbnails-regenerator.php on line 630
[18-Dec-2017 17:54:09 UTC] PHP Warning: Illegal string offset ‘full’ in /home2/lyltsklj/public_html/wp-content/plugins/regenerate-thumbnails/includes/class-regeneratethumbnails-regenerator.php on line 630
[18-Dec-2017 17:54:09 UTC] PHP Warning: Illegal string offset ‘sizes’ in /home2/lyltsklj/public_html/wp-content/plugins/regenerate-thumbnails/includes/class-regeneratethumbnails-regenerator.php on line 641
[18-Dec-2017 17:54:09 UTC] PHP Warning: Invalid argument supplied for foreach() in /home2/lyltsklj/public_html/wp-content/plugins/regenerate-thumbnails/includes/class-regeneratethumbnails-regenerator.php on line 641
[18-Dec-2017 17:54:09 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /home2/lyltsklj/public_html/wp-content/plugins/regenerate-thumbnails/includes/class-regeneratethumbnails-regenerator.php:630) in /home2/lyltsklj/public_html/wp-includes/rest-api/class-wp-rest-server.php on line 1248

The images in question are 1080 x 4876 and 1080 x 4289. This might have something to do with it?

Hmm, let me get back to you guys after I investigate some more.

after update still same the issue

I have also updated to 3.0.1 and problem persists.

I have the same issue. I saw that the following address was being called to get the IDs:

/wp-json/wp/v2/media?page=1&per_page=25&_fields=id&is_regeneratable=1&exclude_site_icons=1&orderby=id&order=asc

I tried messing with this and when I take off the end ‘&order=asc’ then the server stopped coming back with a 500 error and the IDs load

Can’t say why though