Dimensions runs by handshaking the Citrix client installed on the PC with a server Client and these need to be running applicable versions.
To resolve this, restart the PC and clear cache and cookies in the browser before logging into Access Evo.
Tip: If the problem persists then review the installed Citrix client in Windows - Settings - Add/Remove Programs or Apps, and compare the version with a working user.
Typically the failing user will have an older version, uninstalling Citrix and clearing cache and cookies will prompt a new install of the Citrix client when accessing Dimensions from Access Evo.
If the issue still persists, then please install the following version of Citrix:
Once this is downloaded, go to cmd prompt and type (may require your IT Team):
CitrixWorkspaceApp.exe /cleaninstall
This will clean up the old version and install the above version.