Web-panels do not seem to load properly when referencing a velocity template that is bundled with the plugin

Affects Confluence as well.

Raised by external plugin developer:

Web-panels do not seem to load properly when referencing a velocity template that is bundled with the plugin, we are using web panels for the display on the project page as well as in our configuration wizard, it seems to be working well when first installed into the JIRA instance, however, if we upgrade (or uninstall then reinstall) the plugin via UPM, the web-panels stops working, the error received is that it cannot find the velocity template. Tracing the code back into the ModuleDescriptor, from the flow of the install/uninstall process, it seems like it might be that it is not updating the referencing classloader correctly when it is loaded the second time, thus it cannot find the specified resource in the plugin, our current workarounds for this is to either restart JIRA or instead of using a velocity template, embed the velocity template within the atlassian-plugin.xml (we have opted to embed it into the atlassian-plugin.xml, but the risk here is that this file is parsed by maven to inject values, so if a parameter declared in the pom.xml is used in the code, it will class and the maven parameter will be displayed instead), I have experienced this with both JIRA 4.4 as well as Confluence 4.0.