predecessor and successor assign widows not opening

Primavera P6 15.2 Standalone install using the SQLite database, the successor and predecessor assign buttons do not open when not initially connected to a network.  After connecting to a network, the assign widows open.  After removing Ethernet cable from computer, widows still open. After rebooting computer and not connecting Ethernet cable, problem returns.  Other installations do not have the problem.  Has anybody experienced this phenomenum?