Problem validating certificates in VPOP3 Enterprise SSL settings

> When trying to replace the SSL certificate in VPOP3, I get the following error:

> Error verifying certificate chain

There was a problem with the validation routine in v6.17-v6.19 with some certificates. This problem should be fixed in 6.20

You can edit the HTML file to disable the validation so VPOP3 just accepts the certificate even if it's wrong as it did with 6.16 and earlier. To do this, open the VPOP3\_webmail\admin\services.html file in a text editor (eg Notepad) . Find line 105 which says
window.Validate = function Validate() {
Just after that line, add another line which says: 
return true;
Then reload the Services settings page and try again