{"id":3284,"date":"2025-10-02T10:30:52","date_gmt":"2025-10-02T10:30:52","guid":{"rendered":"https:\/\/cert-mu.govmu.org\/cert-mu\/?page_id=3284"},"modified":"2025-10-02T10:31:44","modified_gmt":"2025-10-02T10:31:44","slug":"microsoft-outlook-bug-on-windows-devices-results-in-repeated-email-crashes","status":"publish","type":"page","link":"https:\/\/cert-mu.govmu.org\/cert-mu\/?page_id=3284","title":{"rendered":"Microsoft Outlook Bug on Windows Devices Results in Repeated Email Crashes"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-page\" data-elementor-id=\"3284\" class=\"elementor elementor-3284\" data-elementor-post-type=\"page\">\n\t\t\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-c277fe8 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"c277fe8\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-98265d2\" data-id=\"98265d2\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-98c92c5 elementor-widget elementor-widget-text-editor\" data-id=\"98c92c5\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Microsoft is currently investigating a significant bug affecting classic Outlook for Windows that prevents users from accessing their email accounts.<\/p><p>The issue manifests as a persistent error message stating \u201cCannot start Microsoft Outlook. Cannot open the Outlook window. The set of folders cannot be opened. The attempt to log on to Microsoft Exchange has failed.\u201d<\/p><p>The error appears when users attempt to launch the traditional Outlook desktop application on Windows devices.<\/p><p>According to Microsoft\u2019s official documentation updated on September 26, 2025, this particular error can occur for various reasons, but recent support cases have primarily involved user mailboxes experiencing authentication failures.<\/p><p>Microsoft has identified specific technical indicators to confirm whether users are experiencing this particular issue.<\/p><p>Technical diagnostics reveal the error stems from a \u201cClientBackoffException\u201d where the authentication concurrency limit is reached, causing the Exchange server to reject connection attempts.<\/p><p><strong>Read More:<\/strong><\/p><p><a href=\"https:\/\/gbhackers.com\/microsoft-outlook-bug-on-windows-devices\/\">https:\/\/gbhackers.com\/microsoft-outlook-bug-on-windows-devices\/<\/a><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Microsoft is currently investigating a significant bug affecting classic Outlook for Windows that prevents users from accessing their email accounts. The issue manifests as a persistent error message stating \u201cCannot start Microsoft Outlook. Cannot open the Outlook window. The set of folders cannot be opened. The attempt to log on to Microsoft Exchange has failed.\u201d The error appears when users attempt to launch the traditional Outlook desktop application on Windows devices. According to Microsoft\u2019s official documentation updated on September 26, 2025, this particular error can occur for various reasons, but recent support cases have primarily involved user mailboxes experiencing authentication\u2026<\/p>\n","protected":false},"author":7,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-3284","page","type-page","status-publish","hentry"],"blocksy_meta":"","_links":{"self":[{"href":"https:\/\/cert-mu.govmu.org\/cert-mu\/index.php?rest_route=\/wp\/v2\/pages\/3284","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cert-mu.govmu.org\/cert-mu\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/cert-mu.govmu.org\/cert-mu\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/cert-mu.govmu.org\/cert-mu\/index.php?rest_route=\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/cert-mu.govmu.org\/cert-mu\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3284"}],"version-history":[{"count":4,"href":"https:\/\/cert-mu.govmu.org\/cert-mu\/index.php?rest_route=\/wp\/v2\/pages\/3284\/revisions"}],"predecessor-version":[{"id":3289,"href":"https:\/\/cert-mu.govmu.org\/cert-mu\/index.php?rest_route=\/wp\/v2\/pages\/3284\/revisions\/3289"}],"wp:attachment":[{"href":"https:\/\/cert-mu.govmu.org\/cert-mu\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3284"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}