"Move To Folder" Never Completes Task; Locks eM Client

eM Client version 8.1.1083 (c197f89) running on Mac Mojave 10.14.6…
When attempting to “Move To Folder” (drag-and-drop OR dialog from menu) on a mail in the inbox to a local folder, the task posts the Copying Items message, “This operation may take a while to complete. Please be patient.” The task never completes. When eM Client is given a “Quit” command to override, the application hangs and will not respond to macOS. “Force quit” will drop the application – but when restarted, the “Move To Folder” issue remains.

Okay…so what am I missing? Thanks for the help!! Bobby C