An error appeared after the latest updates. But I can't catch her. It showed when navigating between pages. In my case, only after the NavigateTo page. And it's strange that only when the user is not logged in. If the page is reload after the exception, the page loads normally (that is, the problem is not in the page code).
I'm afraid that I'm unable to reproduce such exception in both our demos and Radzen generated application with security. If you have Radzen subscription you can send us you app at info@radzen.com to check locally what's going on.
I can confirm I am encountering this same exception in my application. Thanks for the suggestion to invoke TooltipService.Dispose() as a workaround. I added it to bottom of MainLayout.razor because I was seeing the bug exception intermittently when navigating between pages. This seems to have worked around the problem. (See below).
I am a paying subscriber and I recall the recent Radzen update that added TooltipService because I had to manually add it to my Startup.cs (I have that file on code gen ignore list and I encountered startup errors until I added it). (Can't send my app to Radzen due to dependencies; currently in dev, working locally).
Sometime in the past few recent updates since then I started to encounter this Tooltip related bug. (First noticed it Fri. 9/18 during a demo, of all times..)
Added this code to bottom of MainLayout.razor so that it's called on every page render. Fixes the issue:
Please send us your app if possible at info@radzen.com to check whatโs going on.
UPDATE: We were able to reproduce and fix the issue in latest Radzen.Blazor.