I could fix this issue, the windows forwarder was actually configured as LightForwarder and was still operating in LightForwarder Mode, ( this was done by someone previously) and at the sametime I was using the SplunkWebUI for this particular server, which was causing these events.
Solution: I disabled splunk-light forwarder and enabled forwarder mode, the issue got resolved
This is a defect in 4.1.x, the message happens when you restart a LWF. I have been able to replicate the issue. It has been reported to support and is being investigated by engineering. This has been added to the known issues document, see SPL-37337: