Most often, the problem is due to the user unintentionally affecting their Sketchbook files while using the Android Photo Gallery app.
This message appears when your Sketchbook files have been moved, renamed or deleted from outside of Sketchbook.
For every piece you create in Sketchbook, two files are saved - the layered TIFF file that is your art data, and a flattened PNG preview image that displays in the Sketchbook Gallery.
Photo gallery apps search for images across device folders and display them in the gallery. Because all Sketchbook files are images, they will appear in the gallery app.
TIFF files can be displayed with a generic image icon:
Some people delete these Sketchbook files from inside their Android Photo Gallery because they don't recognize the icon or believe it to be a corrupted file.
These files are not corrupted. These are your layered Sketchbook art files. AndroidOS does not have the ability to "preview" a TIFF image, which is why the icon doesn't look like your art.
Moving, deleting or renaming these files will break their connection with the Sketchbook Gallery and they will no longer open in Sketchbook.
How to keep your Sketchbook files from appearing in the Photo Gallery app
The Samsung Gallery app will allow you to hide a folder if you don't want to see your Sketchbook files. Google Photos has a similar function.
Do Not add a ".nomedia" file to the folder as a workaround. Doing so will cause Sketchbook's Gallery to not be able to scan and recover its files.
Fixing this issue
If a file was moved
If a TIFF file is moved into another folder on the device, the Sketchbook Gallery will not be able to locate it. Clicking on the preview in the Sketchbook Gallery will generate the error message because the linked TIFF file is not where Sketchbook expects it to be.
You can move TIFF files back to the /Pictures/Sketchbook Gallery folder to restore the connection to the Sketchbook Gallery.
If a file was deleted
If a TIFF file is deleted from the Android Photo Gallery or from the File Manager, clicking on the preview in the Sketchbook Gallery will generate an error message because the linked TIFF file has been manually deleted.
You must recover the photo from the Photo Gallery Trash
Note: deleted files on Android are often automatically removed from Trash after 30 days and would become unrecoverable
If a file was renamed
If you renamed a Sketchbook TIFF file in your Android Photo Gallery, that will break its connection to the Sketchbook Gallery and the file will appear to be missing from Sketchbook.
In the Android Photo Gallery details of the file you want to restore, check to see if the renamed TIFF remains in the /Pictures/Sketchbook Gallery folder. If it does, go to Sketchbook > Preferences and use the Gallery Image Recovery tool.
This will identify any unconnected TIFF files in the folder and restore them to the Sketchbook Gallery in a new folder called “Recovered”.
Alternatively, you can restore the original name of the TIFF, and therefore the connection to the Sketchbook Gallery. The original name with be the same as the PNG image with only the differing file extension at the end. This will restore the connection to the Sketchbook Gallery.
After running the Gallery Image Recovery tool, go to your Sketchbook Gallery and tap on the title to show your folders. Any recovered images will appear in a new folder called "Recovered".
