No default application

Hello, this could be a simple thing and apologies if its been already covered. I have a Sandisk Ultra usb3.0 and use it on an IMac running High Sierra.

i downloaded secure access and transferred 30 or so photos (jpegs) yesterday. Today on using it i click on an image and all i get is a message saying

There is no default application to open the document…and two options…cancel or choose app. ive tried choosing photoshop elements but it does not show anything

As a newbie doing this, is there a simple thing to do to fix this?

Not a Mac user so I don’t know if things work similar to Windows but to access a file within SecureAccess with an app one has to extract the file from the vault using SecureAccess.  hth