You can find the progress bar at the bottom of the app. It takes the desktop one to two hours to complete the first synchronization. The entire blockchain will be downloaded.
To synchronize, the app must remain open. When you close it, the process stops.
If there is no progress, then the used (maybe public) WIFI has a too strict firewall that blocks the network traffic with the Gulden blockchain like a WIFI network at your work, university or library. Then move to another WIFI network at home, for example.
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