Hi @jaisonbabu,
thank you for the additional information:
The first problem seems to be this:
This won’t work with java 11, as those packages are no longer available. There is an official replacement available at java.util.Base64
.
Have you converted the build of your extension to java 11 (as described in Preview KNIME AP 4.4 -- Java 11 & Eclipse Upgrade)?
If yes, then you should have seen a compilation error at this point.
If that doesn’t work, I suggest debugging the plugin activation / license verification process with 4.3 and 4.4 in parallel. So that you can see if the security code shows different behavior.
best,
Gabriel