Are you working with Premiere Elements 12 Windows or Mac?
If Mac, there is not Chroma Key, Green Screen Key, or Blue Screen Key.
If Windows...you need to be in the Expert workspace in order to find and use the Keying Effects,
such as Green Screen Key.
Please review and consider, and then let us know the outcome.
Add On....Have you installed the 12.1 Update for 12? If not, please do so using an opened project's Help Menu/Update.
One of the fixes will be for the Text Style issue of the Expert workspace.
Thank you for your answer. I have the mac version so that explains it.
Do you know the reason why there is no green screen function in the mac version, and do you know a alternative for green screen on mac ?
Thanks for the reply. Glad you asked. Please check out my blog post on the use of the Difference Matte, especially for the Premiere Elements Mac users who run into this Windows Only situation.
We are not Adobe. Rather user to user. So, I am not sure why these keying features are not included in Premiere Elements Mac.
Please review and consider the above, and, if any questions, please do not hesitate to ask.