Undefined subroutine &UNIVERSAL::ref::_hook called at /ModPerl/RegistryCooker.pm line 288

Hey there, I'm getting random but sequential internal server errors,
which Apache logs showing: 

Undefined subroutine &UNIVERSAL::ref::_hook called at
/usr/local/lib/perl5/site_perl/5.24.1/x86_64-linux-thread-multi/ModPerl/RegistryCooker.pm
line 288 

After refreshing the browser, the errors may continue a few times and
then resolve themselves. Later on they return. The pattern has not been
discernible. The server is not under heavy load. 

Any ideas? 

-- 
Christopher Bragg
 Ketro Venture
  (905) 228 0491