Lost a circuit

[Mtneer]

Nothing has changed regarding outlets (all original from 20+ years ago). Only one is gfci and reset did nothing, all indoors. The circuit just blinked out in the middle of the day with no provocation from us.

I'll check lighting strings but can that kill the circuit when they aren't powered in middle of the day? All LED so draw is low.

Edit to add: Yep, gfci is tripping for the outlet that has the main string of lights (same set for several years, worked fine until today). Only one gfci on the circuit. Didn't think it would take everything else down.