I am getting following error while booting up the server. Application has Spring as well as AspectJ classes in it.
Caused by: java.lang.VerifyError: JVMVRFY0
Well, I'll write it here again as my first reply was deleted without any explanation though it was the correct one.
Given the exception you encounter you're likely at WAS 8.5.5.0. There's a known issue documented under APAR PM90932 about this. An ifix has been publisehd for this issue and you can read about it and download it from here. Once the ifix is installed, the issue won't appear again.