Thanks for the response!
The firmware and the device driver was not on the latest version. We upgraded both components on last Monday, Apr. 01 to the latest version.
We also experienced the problem sometimes during the year 2018, but it was much lower frequent then this year.
The symptom is: A Flexnet based license server stops with detecting USB dongle removal. (The USB dongle provides the hostID for the license server. The server is a virtual machine, the USB dongle is connected to the VM via AnywhereUSB/14.)
The two log lines I attached previously are from the Codemeter log. The Codemeter is the device driver of the USB dongles. Our plan is to compare/associate the logs from the different protocol levels like License manager, Codemeter, AWUSB, network at the next actual time of problem.