Last month, Microsoft acknowledged that some users running the latest version of Windows 10 had problems with the Start menu and the Windows search. These problems arose after Patch Tuesday last month, but surprisingly, Microsoft then marked these problems as "resolved."
"At this time, Microsoft has not found a search or startup problem that significantly affects users originating in KB4515384," the company said in the Windows Health Panel on September 19. "We will continue monitoring to ensure that users have a high quality experience when interacting with these areas."
As a result, some users of Windows 10 version 1903 are still experiencing problems with the start menu. In a post on the Microsoft Answers website that saw Windows Latest (via ZDNet), a Microsoft engineer responded to a user who reported a critical error after installing Patch Tuesday this month. "We are aware of this problem and we estimate that a resolution will be released at the end of October," said the Microsoft employee on October 12.
At the time of writing, Microsoft has not yet updated the release notes for this month's patch Tuesday (KB4517389) to mention these persistent problems with the Windows 10 Start menu. It is still unclear if the problem is very widespread, but hopefully Microsoft will finally fix it in the next patch for Windows 10 version 1903.
Additional reading: Start menu, Windows 10, Windows 10 Update May 2019