crowd authentication is not working

[vivuu]

After migrating from Windows to linux , for all atlassian applications we are not able to connect to crowd server for enabling the authentication under the user directories.

We suspect that, in previous environment the applications where running behing proxy, So in current environment there is no proxy. 

So in crowd and ther applications where we can change the proxy settings to null.

[Nic Brough -Adaptavist-]

It's hard to say without a proper set of logs, but it looks to me like you have not set the Crowd base url correctly for the connection - that %crowd% thing in that string should have been replaced with a valid crowd server address.  I'd guess you've put in an invalid or escaping character (as you can't leave it blank)