Authenication Ptroblem

I'm running Essentials on a private network pointed at two different farms.  One farm using  Claims authenication and one uses Windows authenication.

The also use custom identify providers.  this was all working until recently.

It gives a error when authenticating to either farm.  It works for others on my network who have similar configurations and go to the same sites/farms. (They are same patch level on Win 10 as me).

I deleted the installation including the workspace .metavis folder.  No joy    No upgrades to the product since about a year ago and no changes to the server (it works for others you recall).

When attempting with claims, it cannot find the page to connect to (normally site contents)   With attempting with windows authentication, it prompts for userid/password/domain (normally doesn't ask for that), then gives "Connection failed: Null" if I enter or do not enter userid/password/domain.

Fails if I login with IE prior (I normally use Firefox, this wasn't required previously however).

Environment:  Win 10, SP 2013 on both farms, - Cannot provide logs, captured SSL, etc from this network.