After upgrade PowerConnect UI shows “500 Internal Server Error”

In the logs you see the text

Issue is caused by caching of the ws policy in NetWeaver java engine. The ws cache needs to be flushed using this KB article below. This issue only occurs when using SUM to update the application, using telnet to deploy the application this issue does not occur.

https://www.powerconnect.io/wiki/kb-079-ui-ws_policy-error-after-upgrade/