This indicates that Citrix is not behaving correctly and needs to be reinstalled. To reinstall it, follow the steps below:
Log out of Access Evo.
Open Windows Control Panel.
Click Programs and Features.
Right-click Citrix Workspace YYYY, where YYYY is a year number of your installed version.
Select Uninstall and then click Confirm you wish to make changes.
Open a new tab in your Web browser.
Go to the Citrix downloads page.
Click the link for the entry underneath Access Evo app for Windows Current Release.
On the next screen click the Download Citrix Workspace app for Windows button.
Once CitrixWorkspaceApp.exe has downloaded, double-click it to run and follow the instructions.
Login to Access Evo and open Dimensions as usual.