Server Error when adding any new pattern

I’ve successfully added several custom patterns using the desktop app, and then the mobile app. The patterns drew successfully on Oasis Mini device. Now, any new pattern I try to create with a .rho extension produces a Server Error on the Oasis Mini desktop app in Windows 10. I’ve even tried other .jpg files that had created successful patterns and drawings previously. Also, not image is shown in the preview area now after I choose a .jpg file.