I yesterday updated one of my Workstation installations to the latest version 15.5.6. Since that I have one VM on an ESXi 6.0 host with VM-Version 11 running Windos 10-32bit, where I cannot not open a console from Workstation. It throws an internal error and in the mks-log you see a message like (from memory as this PC is down at the moment) “VNC connection password required but none provided”. In the end I copied the excutables and libraries from a WS15.5.1 installation to another directory on this PC and started Vmware workstation from this directory and all was working as before. But if I use the WS 15.5.6 executables the connection fails.
Interestingly I can open consoles to the other VMs on this ESXi 6.0 host (being Windows server 2016 und various Linux servers) without problems with the WS15.5.6 executeables.