Welcome to the forum.
Now, PrE does not have a TWAIN, or any other protocol for a scanner. I am not sure what has happened.
Did you scan into PSE (Photoshop Elements)? PrE (Premiere Elements) should not come into play with this.
What video camera are you attempting to attach? What errors does PrE give you?
Please tell us about your TWAIN and WIA setup on your computer. There might be something there.
WHERE is it listed as your primary source?
I also would like to help resolve you issues, but you will need to supply the details of what you are doing and how you are doing it.
As a start, what programs are involved…Photoshop Elements and/or Premiere Elements and what versions? What is your goal?
a. scan photos with a scanner and import them into Photoshop Elements Organizer and then into Premiere Elements
b. scan photos with a scanner and save them to your computer hard drive
You say “A couple of weeks ago I scanned a picture into my computer”
Question: To where did you scan your photo: computer hard drive, Photoshop Elements Organizer and computer hard drive, or other?
You say “Since then I can not download my pictures to Adobe.”
Question: Where are those scanned photos located and what is the Adobe program that you want to download your photo(s) into? Do you mean import your photos in Photoshop Elements or Premiere Elements?
You say “The scanner is listed as the primary source.”
Question: Are you seeing that in the Properties of the Photoshop Elements Organizer or somewhere else?
I am going to suggest a possible workflow for Photoshop Elements and Premiere Elements with regard to scanned photos. Let us see if this is what you may be trying to do:
1. Place your photo in your scanner.
2. Open Photoshop Elements Organizer, go to File Menu/ Get Photos and Videos/ From Scanner.
3. In the “Get Photos from Scanner Dialog” that opens, set up for:
a. Scanner name
b. Save Files in:
c. Save As
d. Automatically fix Red Eyes
and click OK.
4. Scan dialog box will appear. Set that up and click OK.
5. Scan takes place with the end result being your photo appearing in the Photoshop Elements Organizer as a thumbnail. The “real” image has been saved to the computer hard drive, default location = My Pictures/Adobe Folder/Scanned Photos.
If you want to get those scanned photos into Premiere Elements, here are two possible ways:
a. In the Photoshop Elements Organizer, select/highlight the photo or photos that you want to import into Premiere Elements. Then go to the File Menu/click on Send to Premiere Elements. Premiere Elements will open automatically. And, after you set your project preset in new project dialog, it will receive the photos.
b. Close Photoshop Elements. Open Premiere Elements, select your project preset in the new project dialog, then use Get Media/Files & Folders to bring in your photos from My Pictures/Adobe Folder/Scanned Photos.
I suspect that this is the scenario that you are trying to use. But, we will never know unless you tell us the details requested.
Please update us on your progress.