This picks my interest as I have the same issue on my company laptop. I don't see this on another laptops. Would be nice to find out what the solution is for this. Jab4win 10.6.2
Apparently this has something to do with the time setting on my laptop and the certificates. We have an internal CA and use Jabber for Windows. This appears to only be a problem on Windows 10 and for whatever reason was only happening on my laptop and Surface Pro which were both upgraded to Windows 10 recently. I went through and blew away all of the certificates on my machines and copied certs from another laptop that we knew that worked in the same trust stores on our machines. That did not fix it. Tried uninstalling and reinstalling from 11.0.1 to 11.5 and then finally decided to go back to 10.5.5 and then all of a sudden it would work with cert errors. After we installed 10.5.5 we decided to re-install 11.0.1 to see what would happen and that started working with cert errors (different message). Then uninstalled that and went to 11.5 and that appeared to work. Also noticed on my machine that the date and time for "setting the time zone automatically" was turned off. The time looked and appeared correct to me but changed this setting to ON. From this point, my Jabber for Windows is working but reports invalid certificates for the jabber servers. No one else in our company has this issue but me. Still not sure why but it is pointing directly to my Windows 10 upgraded from Windows 7 machines. I think it is a security setting and/or time setting somewhere but can not narrow it down. Not all features work such as WebEx but the IM portion is working. If anything else develops I will update but since no one else has anything on this on the web anywhere, I thought I would share.
Root cause is most likely your certificates are no longer FIPS-compliant, and your local system crypto policy is set to enforce FIPS compliance. Either update your certificates to meet current FIPS compliance, or disable the local policy (not recommended for obvious reasons).
Here is the step by step to disable FIPS. That will do the trick.
Using an account that has administrative credentials, log on to the computer.
Click Start, click Run, type gpedit.msc, and then press ENTER.
In the Local Group Policy Editor, under the Computer Configuration node, double-click Windows Settings, and then double-click Security Settings.
Under the Security Settings node, double-click Local Policies, and then click Security Options.
In the details pane, double-click System cryptography: Use FIPS-compliant algorithms for encryption, hashing, and signing.
In the System cryptography: Use FIPS-compliant algorithms for encryption, hashing, and signing dialog box, Double click Enabled, Select Disabledand then click OK to close the dialog box.
