{"id":17259,"date":"2026-07-11T03:01:25","date_gmt":"2026-07-10T18:01:25","guid":{"rendered":"https:\/\/m365jp.net\/?p=17259"},"modified":"2026-07-11T03:02:37","modified_gmt":"2026-07-10T18:02:37","slug":"servicedegradation-mo1420954-microsoft-365-suite-users-are-unable-to-access-microsoft-copilot-web-and-m365-cloud-microsoft-3","status":"publish","type":"post","link":"https:\/\/m365jp.net\/index.php\/2026-07-11-servicedegradation-mo1420954-microsoft-365-suite-users-are-unable-to-access-microsoft-copilot-web-and-m365-cloud-microsoft-3","title":{"rendered":"[serviceDegradation] MO1420954 | Microsoft 365 suite | Users are unable to access Microsoft Copilot web and m365.cloud.microsoft"},"content":{"rendered":"
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MO1420954 | Microsoft 365 suite | Users are unable to access Microsoft Copilot web and m365.cloud.microsoft<\/th>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n\n\n\n\n\n\n\n\n\n\n
Status<\/th>\nserviceDegradation<\/td>\n<\/tr>\n
Classification<\/th>\nincident<\/td>\n<\/tr>\n
User Impact<\/th>\nUsers may be intermittently unable to access Copilot web and other pages that redirect to the m365.cloud.microsoft URL.<\/td>\n<\/tr>\n
Last Updated<\/th>\n07\/10\/2026 17:52:50<\/td>\n<\/tr>\n
Start Time<\/th>\n07\/09\/2026 01:27:54<\/td>\n<\/tr>\n
End Time<\/th>\n<\/td>\n<\/tr>\n
Latest Message<\/th>\nTitle: Users are unable to access Microsoft Copilot web and m365.cloud.microsoft<\/p>\n

User impact: Users may be intermittently unable to access Copilot web and other pages that redirect to the m365.cloud.microsoft URL.<\/p>\n

More info: Access eventually times out with an error message stating, “Bad Request – Header Field Too Long. HTTP Error 400. A request field is too long.”<\/p>\n

The impacted URL is m365.cloud.microsoft and other URLs which redirect to this page, including but not limited to:
– office.com
– portal.microsoft.com <\/p>\n

Users may be using URLs such as office.com and the navigation Waffle to access M365 applications in the browser, such as Outlook. For this scenario, when the URL redirects to m365.cloud.microsoft they may experience impact, however, users can access M365 applications in the browser directly through the product\u2019s specific URL (such as: outlook.office.com).<\/p>\n

As a potential workaround, users can use the desktop version of the Microsoft 365 applications. Additionally, users may experience temporary relief by refreshing the cache when trying to access through the browser.<\/p>\n

Current status: We’re proceeding with the traffic rerouting which we expect to fully remediate impact. We anticipate this process will complete by our next scheduled update. <\/p>\n

Scope of impact: This issue could impact any user attempting to access Copilot web, or a URL which redirects to m365.cloud.microsoft.<\/p>\n

Preliminary root cause: A recent change which modified the route that back-end service calls take when users access the affected apps unexpectedly introduced impact. <\/p>\n

Next update by: Friday, July 10, 2026, at 8:00 PM UTC<\/td>\n<\/tr>\n

Machine Translation<\/th>\n\u30bf\u30a4\u30c8\u30eb:\u30e6\u30fc\u30b6\u30fc\u306fMicrosoft Copilot\u306e\u30a6\u30a7\u30d6\u304a\u3088\u3073m365.cloud.microsoft\u306b\u30a2\u30af\u30bb\u30b9\u3067\u304d\u307e\u305b\u3093<\/p>\n

\u30e6\u30fc\u30b6\u30fc\u3078\u306e\u5f71\u97ff:\u30e6\u30fc\u30b6\u30fc\u306f\u65ad\u7d9a\u7684\u306bCopilot\u306e\u30a6\u30a7\u30d6\u3084m365.cloud.microsoft\u306eURL\u306b\u30ea\u30c0\u30a4\u30ec\u30af\u30c8\u3055\u308c\u308b\u4ed6\u306e\u30da\u30fc\u30b8\u306b\u30a2\u30af\u30bb\u30b9\u3067\u304d\u306a\u3044\u5834\u5408\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u8ffd\u52a0\u60c5\u5831:\u30a2\u30af\u30bb\u30b9\u306f\u6700\u7d42\u7684\u306b\u30bf\u30a4\u30e0\u30a2\u30a6\u30c8\u3057\u3001\u300c\u60aa\u3044\u30ea\u30af\u30a8\u30b9\u30c8 – \u30d8\u30c3\u30c0\u30fc\u30d5\u30a3\u30fc\u30eb\u30c9\u304c\u9577\u3059\u304e\u308b\u300d\u3068\u3044\u3046\u30a8\u30e9\u30fc\u30e1\u30c3\u30bb\u30fc\u30b8\u304c\u8868\u793a\u3055\u308c\u307e\u3059\u3002HTTP\u30a8\u30e9\u30fc400\u3002\u30ea\u30af\u30a8\u30b9\u30c8\u30d5\u30a3\u30fc\u30eb\u30c9\u306f\u9577\u3059\u304e\u308b\u3002\u300d<\/p>\n

\u5f71\u97ff\u3092\u53d7\u3051\u308bURL\u306fm365.cloud.microsoft\u3067\u3042\u308a\u3001\u3053\u306e\u30da\u30fc\u30b8\u306b\u30ea\u30c0\u30a4\u30ec\u30af\u30c8\u3055\u308c\u308b\u4ed6\u306eURL\u306b\u306f\u4ee5\u4e0b\u304c\u542b\u307e\u308c\u307e\u3059\u304c\u3001\u3053\u308c\u3089\u306b\u9650\u5b9a\u3055\u308c\u307e\u305b\u3093\u3002
– office.com
– portal.microsoft.com<\/p>\n

\u30e6\u30fc\u30b6\u30fc\u306f office.com \u3084\u30ca\u30d3\u30b2\u30fc\u30b7\u30e7\u30f3\u306eWaffle\u306a\u3069\u306eURL\u3092\u4f7f\u3063\u3066\u3001Outlook\u306a\u3069\u306e\u30d6\u30e9\u30a6\u30b6\u5185\u306eM365\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u306b\u30a2\u30af\u30bb\u30b9\u3057\u3066\u3044\u308b\u5834\u5408\u304c\u3042\u308a\u307e\u3059\u3002\u3053\u306e\u5834\u5408\u3001URL\u304cm365.cloud.microsoft\u306b\u30ea\u30c0\u30a4\u30ec\u30af\u30c8\u3055\u308c\u308b\u3068\u5f71\u97ff\u3092\u53d7\u3051\u308b\u304b\u3082\u3057\u308c\u307e\u305b\u3093\u304c\u3001\u30e6\u30fc\u30b6\u30fc\u306f\u88fd\u54c1\u306e\u7279\u5b9a\u306eURL(\u4f8b:outlook.office.com)\u3092\u901a\u3058\u3066\u30d6\u30e9\u30a6\u30b6\u5185\u306eM365\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u306b\u76f4\u63a5\u30a2\u30af\u30bb\u30b9\u3067\u304d\u307e\u3059\u3002<\/p>\n

\u56de\u907f\u7b56\u3068\u3057\u3066\u3001\u30e6\u30fc\u30b6\u30fc\u306fMicrosoft 365\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u306e\u30c7\u30b9\u30af\u30c8\u30c3\u30d7\u7248\u3092\u4f7f\u3046\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u3055\u3089\u306b\u3001\u30d6\u30e9\u30a6\u30b6\u7d4c\u7531\u3067\u30a2\u30af\u30bb\u30b9\u3057\u3088\u3046\u3068\u3059\u308b\u969b\u306b\u30ad\u30e3\u30c3\u30b7\u30e5\u3092\u66f4\u65b0\u3059\u308b\u3053\u3068\u3067\u4e00\u6642\u7684\u306a\u5b89\u5fc3\u611f\u3092\u5f97\u308b\u3053\u3068\u3082\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u73fe\u72b6:\u30c8\u30e9\u30d5\u30a3\u30c3\u30af\u306e\u518d\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u3092\u9032\u3081\u3066\u304a\u308a\u3001\u5f71\u97ff\u3092\u5b8c\u5168\u306b\u662f\u6b63\u3059\u308b\u3068\u898b\u8fbc\u3093\u3067\u3044\u307e\u3059\u3002\u3053\u306e\u30d7\u30ed\u30bb\u30b9\u306f\u6b21\u56de\u306e\u4e88\u5b9a\u66f4\u65b0\u307e\u3067\u306b\u5b8c\u4e86\u3059\u308b\u3068\u4e88\u60f3\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n

\u5f71\u97ff\u7bc4\u56f2:\u3053\u306e\u554f\u984c\u306f\u3001Copilot\u306e\u30a6\u30a7\u30d6\u306b\u30a2\u30af\u30bb\u30b9\u3057\u3088\u3046\u3068\u3059\u308b\u30e6\u30fc\u30b6\u30fc\u3084\u3001m365.cloud.microsoft\u306b\u30ea\u30c0\u30a4\u30ec\u30af\u30c8\u3055\u308c\u308bURL\u306b\u30a2\u30af\u30bb\u30b9\u3057\u3088\u3046\u3068\u3059\u308b\u3059\u3079\u3066\u306e\u30e6\u30fc\u30b6\u30fc\u306b\u5f71\u97ff\u3092\u53ca\u307c\u3059\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u4e88\u5099\u7684\u306a\u6839\u672c\u539f\u56e0:\u5f71\u97ff\u3092\u53d7\u3051\u305f\u30a2\u30d7\u30ea\u306b\u30a2\u30af\u30bb\u30b9\u3059\u308b\u969b\u306b\u30d0\u30c3\u30af\u30a8\u30f3\u30c9\u306e\u30b5\u30fc\u30d3\u30b9\u901a\u8a71\u306e\u30eb\u30fc\u30c8\u3092\u5909\u66f4\u3059\u308b\u6700\u8fd1\u306e\u5909\u66f4\u304c\u4e88\u671f\u305b\u305a\u5f71\u97ff\u3092\u3082\u305f\u3089\u3057\u307e\u3057\u305f\u3002<\/p>\n

\u6b21\u56de\u66f4\u65b0:2026\u5e747\u670810\u65e5\u91d1\u66dc\u65e5 \u5348\u5f8c8\u6642 UTC<\/td>\n<\/tr>\n<\/tbody>\n<\/table><\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

MO1420954 | Microsoft 365 suite | Users are unable to access Microsoft Copilot web and m365.cloud.microsoft St […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-17259","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/posts\/17259","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/comments?post=17259"}],"version-history":[{"count":0,"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/posts\/17259\/revisions"}],"wp:attachment":[{"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/media?parent=17259"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/categories?post=17259"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/tags?post=17259"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}