After an upgrade of QlikView 12.10 to 12.20 and above, sometimes a large performance degradation is observed when end users try to access their QVWs using the IE Plugin (however if they use the AJAX client the performance is similar to the previous version)
Issue remains even though IE Plugin client version matches the server version.Environment:
Newer versions of QlikView require IE 11. Even if the customer is running IE 11, if the Document Mode is set to something older (like 10) the effective client is IE 10 the QlikView IE Plugin may present issues.
Verify that the 'Document Mode' in Internet Explorer is set to 11, this is a requirement for QlikView 12.20 and above (its likely this is being controlled by the AD Group Policy).
Open Internet Explorer, open Developer Tools, click the 'Emulation' tab, check that Document Mode is 11.
For further information on how to configure IE to be in the correct mode, reference Microsoft: https://docs.microsoft.com/en-us/internet-explorer/ie11-deploy-guide/use-the-enterprise-mode-site-list-manager