Problems with connection to CF Server or CF Administrator. localhost 127.0.0.1 gives transport errors. Previously everything worked fine

Question

I am using CF11 with CF Builder 3. Windows 10. When I booted up yesterday I could not connect to the CF Server or the CF Administrator, although previously I had no problems.

I get errors:

The 127.0.0.1 page isn’t working 127.0.0.1 unexpectedly closed the connection.

and console errors:

[defaultLocal]:FATAL ERROR in native method: JDWP No transports initialized, jvmtiError=AGENT_ERROR_TRANSPORT_INIT(197)
[defaultLocal]:ERROR: transport error 202: bind failed: Address already in use
[defaultLocal]:ERROR: JDWP Transport dt_socket failed to initialize, TRANSPORT_INIT(510)
[defaultLocal]:JDWP exit error AGENT_ERROR_TRANSPORT_INIT(197): No transports initialized [debugInit.c:750]
[defaultLocal]:Error(12/05 at 10:02:03) Unable to start server. Server startup timed out.

The server is listening on port 8500. I tried changing that, but it did not solve anything.

I can see that administrator/ figures in the directory list http://127.0.0.1:8500/CFIDE/

I am using Opera 41.0. I have checked firewalls, and cannot see anything that would block the communication.

I tried Chrome and Firefox, but the same issue occurs.

I also checked the hosts file, and 127.0.0.1 is listed there.

I have re-booted a number of times, but the issue persists.

Anyone any ideas?