How to fix a seemingly operational electrical outlet that does not have any power.?

I had an electrician install two exterior outlets (not fully exposed to rain) about 10 years ago. This year I went to plug in my Christmas lights and they have no power. They are chained together and are serviced by one breaker in my breaker box. I bought a multimeter and determined that the breaker is functioning with 120v on both wires. I also threw the breaker a few times to ensure that it was not a simple fix. I opened the outlet itself and confirmed that all the wires are connected properly and not corroded. They were in good shape, but the multimeter read no current. Everything looks to be well kept, not damaged, and connected properly. I did not check the second outlet which is wired up to my second story. I'm not sure if a problem up there could affect the power at the first of the two. I'm not sure where to go next...