ERROR_NETNAME_DELETED

[RZP]

I synchronize data from PC 1 with PC 2 using the FreeFileSync program. In the meantime, more than 2.5 million are compared and synchronized if necessary. The data comparison runs quite quickly after starting, but then becomes slower as the volume increases. Once the number of files compared reaches around 2.4 million, the network crashes. The comparison of the data between PC 1 and PC 2 then stops and error messages such as "ERROR_UNEXP_NET_ERR" or "ERROR_NETNAME_DELETED" appear. At the same time, PC 1 no longer has an Internet connection or at best a snail's pace connection. The Windows network problem diagnosis then says "The quality of the network connection may be low". After restarting the Ethernet network adapter, the Internet on PC 1 works again.

I've tried it with a different Fritz!Box, with different network cables, with different network adapters, with SSD instead of HD, via cable, via WLAN, by swapping connections on PC 1, PC2, on the Fritz!Box. But none of that changes anything. In all of these configurations, it's always the case that at some point between 2.4 and 2.5 million files compared are over.

There's also a notebook on the network. If I also synchronize PC 1 with this notebook using FreeFileSync with even more than 2.5 million files, these network crashes don't occur.

The donation version doesn't change the situation either.

I'm really confused as to what the cause is. So far, I've only been able to solve the problem by splitting the data to be synchronized into several tasks.