Dear Sharon, Strahil and Michal, Upgrading to 4.3.4.3-1 did solve the problem. Thank you. — — — Met vriendelijke groet / Kind regards, Marko Vrgotic From: Strahil <hunter86_bg(a)yahoo.com&gt; Date: Wednesday, 10 July 2019 at 14:05 To: Sharon <sgratch(a)redhat.com&gt;, Michal <michal.skrivanek(a)redhat.com&gt; Cc: "Vrgotic, Marko" <M.Vrgotic(a)activevideo.com&gt;, users <users(a)ovirt.org&gt; Subject: Re: [ovirt-users] Re: UI exception when changing Cluster in New VM window Dear Sharon, I think you mean Marko Vrgotic. Best Regards, Strahil Nikolov On Jul 10, 2019 14:19, Sharon Gratch <sgratch(a)redhat.com&gt; wrote: Hi Strahil, Based on the stuck trace in the UI log that you sent, I am pretty sure that this UI exception was already fixed on https://gerrit.ovirt.org/#/c/99463/ for oVirt 4.3.4. So please follow Michal's suggestion to install latest 4.3.5 version for overcoming this issue. Thanks, Sharon On Tue, Jul 9, 2019 at 8:19 PM Michal Skrivanek <michal.skrivanek@redhat.com<mailto:michal.skrivanek@redhat.com>> wrote: can you please try that on 4.3.5 and if it persist open a bug with that ui.log attached? thanks, michal On 5 Jul 2019, at 16:06, Vrgotic, Marko <M.Vrgotic@activevideo.com<mailto:M.Vrgotic@activevideo.com>> wrote: Hi Strahil, I tried what you said and I am still getting an exception. Correct me if I am wrong, but my expectation is following, when creating new VM: * Select cluster * Whether I want to use template or create brand new VM from scratch, list of templates and everything else specific to cluster I selected should be loaded Instead, I get the exception and have to refresh/reload the page. In short, when creating new VM, I am currently locked to a default loaded cluster, which in my case is avshared1. To give you bit more insight into configuration, here are the cluster details: <image001.png> Per cluster: