We get "Invalid XML String" error when logging into Lawson through Citrix when using IE11. We found that if we enable cookies that the issue is resolved. The problem is there isn't a GPO to enable cookies through Citrix. So anytime a users profile is cleared or a new user profile is created they have to manually enable cookies by going to tools -> internet options -> click privacy tab -> click advance button -> then check both cookie check boxes.
Has anyone else run into this issue and if so how was it resolved? The Citrix team is working on upgrading the profile manager to 5.2 which we hope works better with IE11.
We have similar issues connecting to Halogen and Kronos. In both cases enabling cookies resolves the issue.