Enhance/Super Resolution not working on a specific file in CameraRaw

Hi, I'm having a problem enhancing a .jpg file (a composite) with Super Resolution in Camera Raw.  (I've done this successfully many times with other composite files.)  The .jpg was converted from a .psd in Ps. In Bridge, the file appears as a "Ps PSD" icon instead of a thumbnail image, which is unusual.  I don't know why this happened.  Does any of this suggest an underlying problem or possible remedy?  Thanks