Easiest thing to try is reinstalling it.
Did (the FP Tools) change in v19 to support native sideloading, or are you using PhoneDisk?
If you're using PhoneDisk, make sure the Content Viewer is selected as the root location.
To be honest...I'm not sure i believe im using FP tools v19 (i downloaded the FP tools post March 12th). I'm currently trying out the CS5.5 deign premium. The tutorials ive looked at show the content viewer being used but i cant seem to find any ref to it anywhere.
I am having the exact same issue as you are in InDesign CS5.5. My Adobe Content Viewer application is also missing and is not in Applications>Adobe. I am also getting the same error message as you are when trying to use Folio Preview. So I don't repost everything here, pls. view my current thread here. I reinstalled the Folio Producer tools to no avail, and then tried to install the Adobe Content Viewer
by drilling down in the Folio Producer installer (AdobeDigitalPublishing-mul > payloads > AdobeContentViewer-mul > AdobeContentViewer.air) but was not able to because I am now getting THIS following message:
"This application cannot be installed because this installer has been mis-configured. Please contact the application author for assistance."
I am on a Mac with OS 10.7.
Okay...I FINALLY got everything working. I uninstalled and reinstalled Adobe Air. I don't know if that helped as I think I was still unable to manually install Adobe Content Viewer at that point. (Reinstalling the Folio Tools would still not install Adobe Content Viewer either.) The only way I finally got everything to work was by creating a new folder inside Applications and choosing to install the Adobe Content Viewer into THAT folder instead of to the default Adobe folder. Ta-da!! That seemed to do it! I then moved the Adobe Content Viewer into the Adobe folder and now all is working perfectly. I have NO idea why it just would not install into the Adobe folder but at least everything is working now. Hope this helps someone!
Cheers for this...i'll have a look
many thanks for your time