Opening first a test company, closing it then opening the "networked" company file is a workaround.
Also deselecting "show home page" as DUCKS495 posted worked for another computer that later developed the same problem. Thank you "DUCKS495"
Go to Edit, Preferences, Desktop View
- Multiple Windows (if that's what you like) - Selected
- Select Save current desktop
- Deselect Show Home page when opening a company file
