Wagtail升级至4.1.5后页面编辑无内容问题及解决方法

我将Wagtail从2.15.6版本依次升级至3.0.3和4.0.4版本，过程一切正常，仅出现少量测试错误。但升级到4.1.5版本后，在页面编辑界面仅显示内容标题，无法看到内容，且后端日志中无报错信息。

以下是超级用户尝试登录（无输入框时）的日志：

[08/May/2023 08:49:29] "GET /admin/ HTTP/1.1" 302 0
[08/May/2023 08:49:30] "GET /admin/login/?next=/admin/ HTTP/1.1" 200 9147
[08/May/2023 08:49:30] "GET /static/core/css/global.css HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/wagtailadmin/css/core.css?v=824298ec HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/wagtailmedia/css/wagtailmedia-comparison.css?v=824298ec HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/core/css/environment_dev_theme.css HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/wagtail_modeltranslation/css/page_editor_modeltranslation.css HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/core/css/editor.css HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/wagtail_modeltranslation/css/admin_patch.css HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/wagtailmedia/css/wagtailmedia.css?v=824298ec HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/wagtailadmin/js/vendor/jquery.datetimepicker.js?v=824298ec HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/wagtailadmin/js/vendor/jquery-3.6.0.min.js?v=824298ec HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/wagtailadmin/js/vendor/jquery-ui-1.13.2.min.js?v=824298ec HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/wagtailadmin/js/vendor/jquery.autosize.js?v=824298ec HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/wagtailadmin/js/vendor/bootstrap-modal.js?v=824298ec HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/wagtailadmin/js/vendor/bootstrap-transition.js?v=824298ec HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/wagtailadmin/js/vendor/tag-it.js?v=824298ec HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /admin/jsi18n/ HTTP/1.1" 302 0
[08/May/2023 08:49:30] "GET /static/wagtailadmin/js/core.js?v=824298ec HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/wagtailadmin/js/vendor.js?v=824298ec HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/wagtailadmin/js/wagtailadmin.js?v=824298ec HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/wagtailadmin/js/telepath/telepath.js?v=824298ec HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/wagtailadmin/js/sidebar.js?v=824298ec HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /static/wagtailadmin/images/wagtail-logo.svg?v=824298ec HTTP/1.1" 304 0
[08/May/2023 08:49:30] "GET /admin/login/?next=/admin/jsi18n/ HTTP/1.1" 200 9154

问题根源在于自定义的fields.html中添加的自定义过滤器，该过滤器会过滤掉页面内容。重新修改该过滤器后，页面编辑界面的内容恢复正常显示。感谢cnn的建议。

内容的提问来源于stack exchange，提问作者user3608184