Have used LibreOffice for several years, on PC Win 10 pro OS. After update, can not open LibreOffice.
Did you Restart your computer after installing LibreOffice if requested? Note that Power off now defaults to hibernate so you really need to Restart.
Have a look at General Installation issues (Windows) to see if any of those issues might have occurred.
Try going to Control Panel\All Control Panel Items\Programs and Features, right-clicking on LibreOffice and selecting Repair.
Some anti-virus programs will prevent programs from running until they have been added to trusted applications/whitelist/Allowed programs/ or some similar setting.You need to add *C:\Program Files\LibreOffice\program\soffice.bin (assuming 64 bit standard install); read your Anti-virus help to find out how to add.