If you updated Hyprland yesterday you likely have to rework your conf file
Looks like there's a breaking change in the syntax of the hyprland.conf file that came from yesterday's update, as now things like blur_passes = ... don't work anymore and need to be just passes = ... inside a blur namespace (not even sure this is the appropriate term?), ie something like:
Mine was updated to that version too. My config snippet was just an example to highlight that prefixes don't work anymore but the blur namespace itself has to be inside decoration, like this: