It was supposed to be so beautiful.
Further users report that activation package with the number KB4517245 has corrupted the system's file search function. In a post published on the Microsoft support forum, we can read that File Explorer can hang and then exit.
"The search box sometimes stutters completely. In Windows Explorer, you can not click it at all. Right-clicking or left-clicking does not work until you force Windows Explorer to restart. The function works for a moment, then stops ", writes one of the users of Windows 10 with a drawback.
"I have the same problem. The search window triggered by the Ctrl + F command also hangs for a few seconds before I can actually enter the text. The same goes for searching in Control Panel. It's very frustrating!", another user translates.
Microsoft has not yet confirmed this problem. It remains to count on the fact that the bug will be removed in the next system update. And may it be installed, because the first patch for Windows 10 (1909) some people could not install.
Source: Microsoft Answers