I also faced the same challenge when migrating my application from 1.6 to 1.7. After huge struggle, we found a fix to address the issue.
Approach 1: Either you can use -XX:-UseSplitVerifier argument will resolve this issue and you don't need to worry about to upgrade the library files.
Approach 2: I have followed the below steps to overcome the issue. Step 1: Identify and keep a list of external libraries consumed by your application. Step 2: Once you identify the list, keep removing one by one external library files and plug in upgraded version library files which will help you to isolate the library which might causing the issue. In my case: j2ee.jar and openjpa-1.2.2 jar files created an issue and then I have upgraded these libraries which had resolved the migration issues.
Hence, It is bit of slow and painful process to figure out which library causing the issue and arrest it.
I hope, this information might be useful because it is based out of my real time experience.