。
Everything's going well.
Literal
All-things well [adverbial-く] is-going.
うまくいく (うまい 'skillful, well' → adverbial うまく + 行く 'go') is the set expression for 'to go well, to proceed smoothly.' The polite ~ています marks it as an ongoing state. 万事 here is the all-encompassing subject.