Some users said they have duplicated menu items in their “Open With …” of the contextual menu, looks like

First, please check whether you have downloaded multiple copies of the same application, Spotlight is your good assistant.

If there is only one copy, the following command would fix it.

1

/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -kill -r -domain local -domain system -domain user

With this command, the database of LaunchService will be rebuilt, and duplicated entries in “Open With…” should disappear.