ezsystems/ezplatform-admin-ui                      v1.4.1
ezsystems/ezplatform-admin-ui-assets               v3.1.0
ezsystems/ezplatform-admin-ui-modules              v1.4.1
ezsystems/ezplatform-design-engine                 v2.0.0
ezsystems/ezplatform-solr-search-engine            v1.5.4
ezsystems/ezplatform-standard-design               v0.1.0
ezsystems/ezpublish-kernel                         v7.4.2

Here's the request sent by ezplatform-admin-ui that fails for one example, in curl format:
curl 'https://REDACTED/api/ezp/v2/bulk' -H 'User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:66.0) Gecko/20100101 Firefox/66.0' -H 'Accept: application/vnd.ez.api.BulkOperationResponse+json' -H 'Accept-Language: en-US,fr;q=0.5' --compressed -H 'Referer: https://REDACTED/ez/content/location/19618' -H 'Content-Type: application/vnd.ez.api.BulkOperation+json' -H 'X-Siteaccess: admin' -H 'X-CSRF-Token: X4WgO2OqQpoLRD_LfAB_N_lj1I958Btim8Uz_zwlYl0' -H 'Origin: https://REDACTED' -H 'DNT: 1' -H 'Connection: keep-alive' -H 'Pragma: no-cache' -H 'Cache-Control: no-cache' --data '{"bulkOperations":{"operations":{"19620":{"uri":"/api/ezp/v2/content/locations/1/43/52/423/19618/19620","method":"MOVE","headers":{"Destination":"/api/ezp/v2/content/trash"}}}}}'

HTTP/1.1 500 Internal Server Error
Date: Tue, 12 Feb 2019 16:28:02 GMT
Server: Apache
X-Content-Type-Options: nosniff
Expires: Sat, 26 Jul 1997 05:00:00 GMT
Last-Modified: Tue, 12 Feb 2019 16:28:02 GMT
Cache-Control: no-cache, must-revalidate, no-cache, private
Pragma: no-cache
Content-language: en-GB
Status: 404 Not Found
Vary: cookie,authorization
X-Robots-Tag: noindex, nofollow
Content-Length: 162
Content-Type: application/vnd.ez.api.ErrorMessage+json
X-Varnish: 296900
Age: 0
Via: 1.1 varnish (Varnish/5.2)
X-Cache: MISS
Connection: close
{"ErrorMessage":{"_media-type":"application\/vnd.ez.api.ErrorMessage+json","errorCode":500,"errorMessage":"Internal Server Error","errorDescription":"Not Found"}}

curl 'https://REDACTED/ez/location/trash' -H 'User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:66.0) Gecko/20100101 Firefox/66.0' -H 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8' -H 'Accept-Language: en-US,fr;q=0.5' --compressed -H 'Referer: https://REDACTED/ez/content/location/19620' -H 'Content-Type: application/x-www-form-urlencoded' -H 'DNT: 1' -H 'Connection: keep-alive' -H 'Upgrade-Insecure-Requests: 1' -H 'Pragma: no-cache' -H 'Cache-Control: no-cache' --data 'location_trash%5Btrash%5D=&location_trash%5Blocation%5D=19620&location_trash%5B_token%5D=REDACTED'

HTTP/1.1 302 Found
Date: Tue, 12 Feb 2019 16:30:35 GMT
Server: Apache
X-Content-Type-Options: nosniff
Cache-Control: no-cache, private
Location: /ez/content/location/19618
Vary: cookie,authorization
X-Robots-Tag: noindex, nofollow
Content-Length: 348
Content-Type: text/html; charset=UTF-8
X-Varnish: 296940
Age: 0
Via: 1.1 varnish (Varnish/5.2)
X-Cache: MISS
Keep-Alive: timeout=5, max=100
Connection: Keep-Alive