This is ok. Adobe Extension Manager fires these warning popups in case of self-signed extensions. Another option is to sign your work with Paid Certificate (see a list of supported providers) (ref: http://www.davidebarranca.com/2014/05/html-panels-tips-10-packaging-zxp-installers/)
thanks for your reply. So I need to buy a commercial certificate to solve this issue.
Thanks and one more question.
I checked the website you provided and found several types of code-signing certificate.
which one should i choose for Adobe creative extension, as file extension for is .ZXP, i did not find any matching certificate.
I think the first one is OK.