Hi @Boony2000, thanks for reaching out to us.
From R20 to R21, as expectable, changes took place in the API which led to adapt R20 examples to be compiled against the newer API. I recommend having a look at Changes in R21 in our documentation and adapt your code or the demo examples consequently if you copied them straightly from R20.
I'm also a bit puzzled by your last reply where you stated that errors were all fixed but you confirm that warnings are still around. Can you clarify what warnings look like? Can you also provide a little bit of context in your code where the warning it's likely to take place?