pgsql-bugs(at)postgresql(dot)org writes:
> ERROR: fmgr_info: function 19053: cache lookup failed
It looks like your declaration for the plpgsql language is messed up;
specifically, the pg_language row is there but the underlying handler
function has been deleted. I'd suggest dropping and re-adding the
language --- see droplang and createlang scripts.
regards, tom lane