Fatal error: Allowed memory size exhausted

Using Feeds to import and create nodes from an xml feed, creating images from an image file field.

Recently - update to php 7.1? Update to Drupal core 7.60? the feeds importers are failing with this error:

Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 6763 bytes) in /srv/bindings/63539f13493841f6b69311247eea39e4/code/modules/system/image.gd.inc on line 256

Disabling the Imageinfo Cache module removes the error.

Drupal 7.60
Feeds 7.x-2.0-beta4
Feeds Tamper 7.x-1.2
Feeds XPath Parser 7.x-1.1
Imageinfo Cache 7.x-3.5

An AJAX HTTP error occurred. HTTP Result Code: 200 Debugging information follows. Path: /batch?id=1359&op=do StatusText: parsererror ResponseText:

Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 6763 bytes) in /srv/bindings/63539f13493841f6b69311247eea39e4/code/modules/system/image.gd.inc on line 256