Steps to reproduce the issue

I upgraded to 5.1 and I am getting these errors. I have reloaded core files and I am not sure if it is missing the en-GB file but it seems to be there. Has anyone else exprienced this?

Here are the errors:

• /language/en-GB/joomla.ini
  lib_joomla
• /language/en-GB/lib_joomla.ini
  plg_system_djjquerymonster

• /administrator/language/en-GB/plg_system_djjquerymonster.ini
• /administrator/language/en-GB/en-GB.plg_system_djjquerymonster.ini
• /plugins/system/djjquerymonster/language/en-GB/plg_system_djjquerymonster.ini

• /plugins/system/djjquerymonster/language/en-GB/en-GB.plg_system_djjquerymonster.ini
  plg_system_kunena.sys

• /administrator/language/en-GB/plg_system_kunena.sys.ini
• /administrator/language/en-GB/en-GB.plg_system_kunena.sys.ini
• /plugins/system/kunena/language/en-GB/plg_system_kunena.sys.ini

• /plugins/system/kunena/language/en-GB/en-GB.plg_system_kunena.sys.ini
  plg_system_regularlabs

• /libraries/regularlabs/language/en-GB/plg_system_regularlabs.ini
• /libraries/regularlabs/language/en-GB/en-GB.plg_system_regularlabs.ini
• /plugins/system/modals/language/en-GB/plg_system_regularlabs.ini
• /plugins/system/modals/language/en-GB/en-GB.plg_system_regularlabs.ini
• /plugins/system/regularlabs/language/en-GB/plg_system_regularlabs.ini

• /plugins/system/regularlabs/language/en-GB/en-GB.plg_system_regularlabs.ini
  plg_system_modals

• /administrator/language/en-GB/plg_system_modals.ini
• /administrator/language/en-GB/en-GB.plg_system_modals.ini
• /plugins/system/modals/language/en-GB/plg_system_modals.ini

• /plugins/system/modals/language/en-GB/en-GB.plg_system_modals.ini
  plg_system_modulesanywhere

• /administrator/language/en-GB/plg_system_modulesanywhere.ini
• /administrator/language/en-GB/en-GB.plg_system_modulesanywhere.ini
• /plugins/system/modulesanywhere/language/en-GB/plg_system_modulesanywhere.ini

• /plugins/system/modulesanywhere/language/en-GB/en-GB.plg_system_modulesanywhere.ini
  plg_system_sourcerer

• /administrator/language/en-GB/plg_system_sourcerer.ini
• /administrator/language/en-GB/en-GB.plg_system_sourcerer.ini
• /plugins/system/sourcerer/language/en-GB/plg_system_sourcerer.ini

• /plugins/system/sourcerer/language/en-GB/en-GB.plg_system_sourcerer.ini
  plg_system_weblinks

• /administrator/language/en-GB/plg_system_weblinks.ini

• /administrator/language/en-GB/en-GB.plg_system_weblinks.ini
  plg_system_gantry5.sys

• /administrator/language/en-GB/plg_system_gantry5.sys.ini
• /administrator/language/en-GB/en-GB.plg_system_gantry5.sys.ini
• /plugins/system/gantry5/language/en-GB/plg_system_gantry5.sys.ini

• /plugins/system/gantry5/language/en-GB/en-GB.plg_system_gantry5.sys.ini
  plg_system_gantry5

• /administrator/language/en-GB/plg_system_gantry5.ini
• /administrator/language/en-GB/en-GB.plg_system_gantry5.ini
• /plugins/system/gantry5/language/en-GB/plg_system_gantry5.ini
• /plugins/system/gantry5/language/en-GB/en-GB.plg_system_gantry5.ini
  files_gantry5_nucleus
• /language/en-GB/files_gantry5_nucleus.ini

• /language/en-GB/en-GB.files_gantry5_nucleus.ini
  tpl_g5_hydrogen_positions

• /templates/g5_hydrogen/custom/language/en-GB/tpl_g5_hydrogen_positions.ini

• /templates/g5_hydrogen/custom/language/en-GB/en-GB.tpl_g5_hydrogen_positions.ini
  tpl_g5_hydrogen

• /templates/g5_hydrogen/language/en-GB/tpl_g5_hydrogen.ini

• /templates/g5_hydrogen/language/en-GB/en-GB.tpl_g5_hydrogen.ini

• /templates/g5_hydrogen/custom/language/en-GB/tpl_g5_hydrogen.ini
• /templates/g5_hydrogen/custom/language/en-GB/en-GB.tpl_g5_hydrogen.ini
• /language/en-GB/tpl_g5_hydrogen.ini
• /language/en-GB/en-GB.tpl_g5_hydrogen.ini
  com_content

• /language/en-GB/com_content.ini
  com_djmediatools

• /language/en-GB/com_djmediatools.ini
• /language/en-GB/en-GB.com_djmediatools.ini
• /components/com_djmediatools/language/en-GB/com_djmediatools.ini

• /components/com_djmediatools/language/en-GB/en-GB.com_djmediatools.ini
  mod_djclassifieds_menu

• /language/en-GB/mod_djclassifieds_menu.ini
• /language/en-GB/en-GB.mod_djclassifieds_menu.ini
• /modules/mod_djclassifieds_menu/language/en-GB/mod_djclassifieds_menu.ini

• /modules/mod_djclassifieds_menu/language/en-GB/en-GB.mod_djclassifieds_menu.ini
  plg_fields_calendar
• /administrator/language/en-GB/plg_fields_calendar.ini
  plg_fields_checkboxes
• /administrator/language/en-GB/plg_fields_checkboxes.ini
  plg_fields_color
• /administrator/language/en-GB/plg_fields_color.ini
  plg_fields_editor
• /administrator/language/en-GB/plg_fields_editor.ini
  plg_fields_imagelist
• /administrator/language/en-GB/plg_fields_imagelist.ini
  plg_fields_integer
• /administrator/language/en-GB/plg_fields_integer.ini
  plg_fields_list
• /administrator/language/en-GB/plg_fields_list.ini
  plg_fields_media
• /administrator/language/en-GB/plg_fields_media.ini
  plg_fields_radio
• /administrator/language/en-GB/plg_fields_radio.ini
  plg_fields_sql
• /administrator/language/en-GB/plg_fields_sql.ini
  plg_fields_subform
• /administrator/language/en-GB/plg_fields_subform.ini
  plg_fields_text
• /administrator/language/en-GB/plg_fields_text.ini
  plg_fields_textarea
• /administrator/language/en-GB/plg_fields_textarea.ini
  plg_fields_url
• /administrator/language/en-GB/plg_fields_url.ini
  plg_fields_user
• /administrator/language/en-GB/plg_fields_user.ini
  plg_fields_usergrouplist
• /administrator/language/en-GB/plg_fields_usergrouplist.ini
  plg_content_jw_allvideos

• /administrator/language/en-GB/plg_content_jw_allvideos.ini

• /administrator/language/en-GB/en-GB.plg_content_jw_allvideos.ini
  plg_content_plgzhosmmap

• /administrator/language/en-GB/plg_content_plgzhosmmap.ini

• /administrator/language/en-GB/en-GB.plg_content_plgzhosmmap.ini
  plg_content_plgzhosmmap_article_overview

• /administrator/language/en-GB/plg_content_plgzhosmmap_article_overview.ini

• /administrator/language/en-GB/en-GB.plg_content_plgzhosmmap_article_overview.ini
  tpl_

• /templates//language/en-GB/tpl_.ini
• /templates//language/en-GB/en-GB.tpl_.ini
  plg_system_cookiesck
• /administrator/language/en-GB/plg_system_cookiesck.ini

• /administrator/language/en-GB/en-GB.plg_system_cookiesck.ini
  plg_schemaorg_article
• /administrator/language/en-GB/plg_schemaorg_article.ini
  plg_schemaorg_custom
• /administrator/language/en-GB/plg_schemaorg_custom.ini
  plg_schemaorg_blogposting
• /administrator/language/en-GB/plg_schemaorg_blogposting.ini
  plg_schemaorg_book
• /administrator/language/en-GB/plg_schemaorg_book.ini
  plg_schemaorg_event
• /administrator/language/en-GB/plg_schemaorg_event.ini
  plg_schemaorg_organization
• /administrator/language/en-GB/plg_schemaorg_organization.ini
  plg_schemaorg_person
• /administrator/language/en-GB/plg_schemaorg_person.ini
  plg_schemaorg_recipe
• /administrator/language/en-GB/plg_schemaorg_recipe.ini
  plg_schemaorg_jobposting
• /administrator/language/en-GB/plg_schemaorg_jobposting.ini
  plg_system_debug
• /administrator/language/en-GB/plg_system_debug.ini

Expected result

Actual result

System information (as much as possible)

Additional comments