Error 500 ajax

Problem/Motivation

I was just browsing the internet and saw that someone has an error similar to mine.

https://www.chartis-research.com/?ajax_form=1

[{"command":"settings","settings":{"ajaxPageState":{"theme":"incisive_chartisresearch","libraries":"eJwDAAAAAAE"},"csp":{"nonce":"JBB4IiqHOotROQGfEXr0aQ"},"pluralDelimiter":"\u0003","user":{"uid":0,"permissionsHash":"b186e40b78798f711520848036b1f14d9ea564361be28864649ae994198b7195"}},"merge":true},{"command":"insert","method":"prepend","selector":null,"data":"\u003Cdiv data-drupal-messages\u003E\n \u003Cdiv role=\u0022contentinfo\u0022 aria-label=\u0022Error message\u0022 class=\u0022messages messages--error\u0022\u003E\n \u003Cdiv role=\u0022alert\u0022\u003E\n \u003Ch2 class=\u0022visually-hidden\u0022\u003EError message\u003C\/h2\u003E\n An unrecoverable error occurred. The uploaded file likely exceeded the maximum file size (2 GB) that this server supports.\n \u003C\/div\u003E\n \u003C\/div\u003E\n \u003C\/div\u003E\n","settings":null},{"command":"invoke","selector":".ief-widget-table","method":"trigger","args":["afterSaveWidget"]}]

In my case it comes out when I use this module: https://www.drupal.org/project/easy_entity_field →