For some companies that are concerned about applications querying information outside their firewall, there is a feature to disable refreshing of the repository. This prevents Vivado from querying the app catalog. In this case users are limited to the current static version of the repo. To disable refresh capability, the following Tcl param can be set in the startup Vivado_init.tcl script for all Vivado sessions:
vivado% set_param tclapp.enableGitAccess 0
After the catalog refresh is disabled, the Refresh button is replaced by the message shown in Disabling Catalog Refresh: Internet access is not available.