[German]A blog reader reports a strange problem. Outlook New is used as an app there. Since the app automatically restarted after an update (must have been to version 1.2025.813.500), it can no longer be opened. It looks as if the VC runtime is causing problems.
A reader report on the problem
Blog reader Sebastian works in corporate IT, where Microsoft's Outlook New is used as an app by users. On August 19, 2025, he contacted me in the late afternoon by email with the subject line "Outlook New no longer starts after an automatic restart of the app." In his email, he wrote: "Since this morning, Outlook New has stopped working for some users after an automatic update."
Martin Geuß reported on this update in his articl Neues Outlook für Windows: Das August-Update bringt neue Offline-Funktionen und mehr on August 18, 2025. According to my information, the rollout of the update has been stopped.
Error in the event log
The reader then checked the event log of the Outlook New app and was shown the log attached at the end of the article. The event log refers to ucrtbase.dll, which comes to the system via the Visual C++ runtime.
IT then unsuccessfully attempted to use an older version of Outlook New in the hope that the correct runtime would be delivered. But this was unsuccessful. Even reinstalling the VC++ Redist components did not change anything.
The reader concluded: "I hope that Microsoft will fix it overnight." My question is whether this is an isolated case or whether more readers are affected?
Further hits
After some searching, I came across yesterday's post New Outlook App 1.2025.813.500 causes crashes in the Eleven forum. There, the person affected refers to the Microsoft post New Outlook doesn't start anymore from August 19, 2025. The solution provided there is to navigate to the %localappdata%\microsoft folder in Explorer and delete the Olk and OneAuth subfolders. Then open the new Outlook app and reset the account.
This helps some people affected by the problem. However, this approach did not work for the person mentioned above, who had to switch to the classic Outlook application.
Issue solved
Addendum: The issue has been solved by an update to version ist 1.2025.818.302 on August 19, or 20, 2025.
The log file from a German system
--- Auszug aus dem Ereignisprotokoll --- Fehlerhafter Anwendungsname: olk.exe, Version: 1.2025.813.500, Zeitstempel: 0x689d590e Fehlerhafter Modulname: ucrtbase.dll, Version: 10.0.26100.4768, Zeitstempel: 0xdbb54def Ausnahmecode: 0xc0000409 Fehleroffset: 0x00000000000a4ace Fehlerhafte Prozess-ID: 0x119B0 Fehlerhafte Anwendungsstartzeit: 0x1DC1103E5E36718 Fehlerhafter Anwendungspfad: C:\Program Files\WindowsApps\Microsoft.OutlookForWindows_1.2025.813.500_x64__8wekyb3d8bbwe\olk.exe Fehlerhafter Modulpfad: C:\WINDOWS\System32\ucrtbase.dll Berichts-ID: 1ecd9334-8cb6-4160-95f9-74e45d4cfef2 Vollständiger Name des fehlerhaften Pakets: Microsoft.OutlookForWindows_1.2025.813.500_x64__8wekyb3d8bbwe Fehlerhafte paketbezogene Anwendungs-ID: Microsoft.OutlookforWindows --- Auszug aus dem Ereignisprotokoll ---
