Steam Beta error

[LT`ProblemSix]

Sometimes I get an error on Team Fortress 2. When I open it, and go to the server browser, it doesn't search any servers but says that Steam Beta must be running to enable server search. I have no idea what that is or how to fix it. Sometimes it appears and sometimes it goes away, if I encounter it again, I want to know how solve this. Thank you.

[True God]

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