You'd be (half-jokingly) amazed at how many people are entirely incapable of understanding and debugging an existing code base.

Like, literally: "Error message has string 'abdc-1234-something-whatever'". They can barely figure out to maybe search the code base for that error message. Unfortunately they can't find the full string. Now they're stuck and can't think of anything else to try.

So, effing, amazing. How do these people ever get through (coding) life? Ever heard of substring search coz error messages frequently have parts that are concatenated/variables inserted? Search for parts of it until you find something. It's not that hard dude, yes the 1234 probably is some dynamic id, so search for just something-whatever and you'll instantly find the relevant code and you can debug further.

But no, this "Senior" can't think of anything when not finding the full string anywhere in the codebase and would rather throw up their hands and let others figure it out.

Either a really dumb "Senior" that somehow got through so far at previous companies or they're silent quitting during probation period already.

If this continues it's not gonna be silent.