As already announced at different occasions (e.g. https://forums.vatsim.net/blogs/entr...-blog-q4-2020/), the legacy VATSIM datafeed has been retired now. This will result in corresponding messages (Error: VATSIM data is older than 20 minutes) in EuroScope (and other applications) because this application has not yet been updated to recognise and work with the new JSON v3 format. To prevent recurring messages of this kind in EuroScope, disable the simulated traffic.