In Access Evo, Dimensions runs under a Citrix app and the app needs to be the correct version. Check with a colleague who is working on what version of the Citrix app they're running and if their version is later, the app should be re-installed.
Logout of Access Evo.
Uninstall Citrix
Clear cache and Cookies - All time (include sites and app data)
Login to Access Evo
Run Dimensions from Access Button and follow the on-screen prompts carefully to install the Citrix app.
If the user still cannot run Dimensions, please raise a new case and reference the title of this article and please include details of the user affected.