A few possible answers for some issues I have seen here... To Poser Preferences, Embedded means Flash. The AIR Library was External. If you set the option to Embedded in the Preferences of the application, it will launch to Flash the next time. Not sure what happens with the edits in Poser.ini

If you are not seeing AppData folder, change your File Explorer View options to Show Hidden Files and Folders. AppData is hidden by default.

With Poser 12 (and 11) you can link to older Libraries using the Add Library option in Poser and selecting the Folder of the Library that contains the Runtime Folder. A few pointers on this....

If you have older scripts, you may encounter some errors on launch after linking the older Library. If you have it as part of your Application Folder, you may want to consider Copying it over to its own folder in the Public Documents (Shared Folder on Mac) and link from there after cleaning up the application files in the Runtime Folder of the Application. Most users of Poser 8 and later should not have this issue unless you intentionally set the Main Library to the Program Files Folder. I will add that before moving, check your User Account Virtual Store Folder for any content... long explanation, but the short of it is Windows may have added content installed or saved to the Main Library to the Virtual Store folder if the Library was in the Program Files folder.

ratscloset
aka John