Jar file not loading at startup

[Macca]

We have a java module based on the cas-client-integration-atlassian that extends the existing Jira login module and allows us to manage our own bespoke single sign-on. The .jar file is deployed by being placed in the /opt/atlassian/jira/atlassian-jira/WEB-INF/classes folder. We have upgraded in our test environment from Jira Software 8.22.6 to Jira Software 9.6.0, but have found that the module appears to be being ignored by the new version of Jira.

Can anyone suggest what may be causing this and how we might be able to get around the problem?

[Fabio Racobaldo _Herzum_]

Hi @Macca ,

if jar is an app, you should install it via manage add ons menu. If it is not an app, you should place it under  /opt/atlassian/jira/atlassian-jira/lib folder 

Fabio

[Macca]

Thanks Fabio. 
I mentioned the wrong location in my original post. I have it in /opt/atlassian/jira/atlassian-jira/WEB-INF/lib/. We have been using this folder successfully since 7.6.3 in Jan 2018, just can't get it to work in v9.
Any ideas? I don't have a /opt/atlassian/jira/atlassian-jira/lib folder.