Hello.
After update my Telerik dll's, i have encountered the exception described in the title (RadPersistenceManagerProxy - Controls should have unique UniqueKey properties).
When i was running the version 2013.1.403.40, my application works good, but running the version 2015.1.401.40, I got the exception described before.
Thanks for your help.
Regards,
Alexis.
5 Answers, 1 is accepted

Note that you need to specify a different UniqueKey for each RadPersistenceManagerProxy. In case you need a Content Page and UserControl and the UserControl is used a couple of time on the page then you can specify a UniqueKey on Page_Load event handler.
I prepared a small runnable sample which demonstrates that and attached it to this forum thread.
Regards,
Kostadin
Telerik

Hello,
I have set UniqueKey to all of my RadPersistanceManagerProxy control. Now I get another error message: Either all proxies should have UniqueKey set or none of them!
What doest it mean all proxies ? Is it control in my ascx which is included in Proxy like: this.RadPersistenceManagerProxy1.PersistenceSettings.AddSetting(RadTreeViewFilterGridColumns);
What is this and how to fix it ? Please help me to solve this issue.
Thank you
Best regards
Vasssek
The cause for this issue is that you need to add a UniqueKey to each RadPersistanceManagerProxy used on the page. In case you are using a same UserControl twice you need to set two different UniqueName to each one of them. Nevertheless, you can remove the UniqueName from the RadPersistanceManagerProxy and this way automatic generated names will be set.
Regards,
Kostadin
Telerik by Progress

Hello,
I have 7 instances of the same user web control (.ascx) nested inside RadMultiPage - each one is inside different RadPageView, of course.
Strange thing is that even RenderSeletedPageOnly is set to true, all user web controls placed inside radpageviews are somehow initialized on server side and that caused be this problem with unique keys and some another problems with saving default state, etc...
I have to load user control programatically in OnInit page method. There I check which radtabstrip is actually selected and then only current one user contorl is loaded. This way it works as expected...
Best regards
Vasssek