In some cases, after upgrading to Jira 7.11.0 and AppLinks 5.4.5, AppLinksManifestDownloader throws a NullPointerException.
Linux OS, Jira 7.11.0 (AppLinks 5.4.5), applink configured to Confluence 6.10.X
We can't reproduce problem locally.
Applinks works without exceptions
The below exception is thrown in the atlassian-jira.log file:
Exceptions becomes visible after setting logging com.atlassian.applinks package to DEBUG level.
Exception is caused by first parameter to ChainingClassLoader constructor being null (see stack trace above), and that parameter is, currentContextClassLoader, which is initialised by Thread.currentThread().getContextClassLoader().
The docs for the `getContextClassLoader` method say that a null return value is possible:
There are two places in the applinks that currently can break if the class loader is null:
AppLinksManifestDownloader#doDownload, line 157
DefaultApplicationLinkService#createReciprocalLink, line 584
No workarounds. A restart may solve the problem for a couple of minutes, but then error reoccurs.