I don't think I can fix that, unfortunately, unless I repost the RPG Traits mod entirely just to remove that incompatibility. Thanks for pointing this out, though!

Currently RPG traits breaks the majority of distant star events, presumably due to it overwriting distant_stars_events.txt with an out of date version.

I found the changes that RPG traits made to distant stars events, if you want to update it. It replaces many of the references to vanilla trait names. e.g. "trait_fleeting" to "trait_fleeting1". I'm guessing this is symptom of the original mod changing the name of the vanilla traits.
Other instances I found were
trait_strong,trait_fleeting,trait_agrarian, and trait_solitary
trait_industrious was renamed to trait_thrift1
trait_adaptave was renamed to trait_robust1

The mod should work without much issue, as long as Stellaris' game structure hasn't changed. Although I've not tested it, it should work in 2.3 through 2.5, and maybe even in earlier versions.

Since the mod for the most part only changes the trait names and descriptions, nothing should have broken nor should it ever break until Stellaris undergoes some major, major overhaul that restructures how modding works down to its foundation.

thanks for your work on this! Is there any way you would consider working on making this compatible with the current version of Stellaris?