Thank you for your post.
When you purchase a licence update, you always receive a new licence key. The licence key pertaining to your older version will no longer be valid.
Both licence keys (the old one and the new one) will appear on your update invoice. The new licence key is always given first. It will typically look like this:
XX-XXXXXX-XXXX, updated from XX-XXXXX-XXXXX
In your case, you would therefore see "[licence key for version 11], updated from [licence key for version 9]".
Please use your new licence key to activate your licence on TeamViewer 11.
I hope this helps. If you encounter any difficulties, please do not hesitate to let me know.
All the best,
... View more