The MS office can crash for whatever reason. Possibly, a third-party app you are using may not be compatible with the frequent updates done by Microsoft. So, if your Office crashes and shows you an error when you try to start it, the easiest fix is to repair it.
1. Press the Windows + X shortcut
2. Select the Apps and Features. This will take you to the list of Apps available in your computer.
3. Scroll down to the MS Office app.
4. Left click on the MS Office app to display the options.
5. Click on Modify. The repair will start once you agree to go ahead with the modification. It may also take some few seconds to several minutes depending on the type of repair being done.
6. Once the repair is done, you are good to continue using MS Office. However, it is advisable to restart you machine first as the Office apps may stutter if you do not.
*This process is for machines that use Windows 10 Pro and updated versions.