Why is the version of Java back levelled in Conf V5.9.1

[Chris Drymalik]

This question is in reference to Atlassian Documentation: Confluence 5.9 Upgrade Notes

It seems to be Java version 1.8.0_65 in Confluence V5.8.15, but is only 1.8.0_51 in V5.9.1.

I'm getting PKIX errors now that seem to be related to a problem in version 1.8.0_51 of Java (suggestions I have seen). The errors in the log definitely didn't occur prior to upgrading to V5.9.1. I'm using a self signed certificate, for SSL, on the server not connected to the internet.

--- additional into

I has never been a problem through multiple version of Confluence (ie. V3 to V5.8.16) and suddenly it is. I don't think it anything to do with the keystore unless that version of java is for some reason pointing in the wrong location. 

In the comments for that article Ioannis Angelakopoulos states that  1.8.0_51-b16 is the problem, and it is fixed by pointing at a different version. When I get a change I will try loading a different version of java and seen what happens. Looking through the java bugs forums, it sort of suggesting it is a know issue with that version of java that is fixed in later versions.

[Volodymyr Krupach]

You get PKIX errors since there is no appropriate certificate/authority in your java keystore. Probably the self-signed certificate was added to your previous Java version and now you have new java with new keystore.

This article should help you to understand and fix the problem: https://confluence.atlassian.com/display/KB/Unable+to+Connect+to+SSL+Services+due+to+PKIX+Path+Building+Failed