We've deployed a test version with the new build. For now the exception did not occur.

Thank You very much for a fast response.

Best Regards

Dear Sir,

this problem should be fixed in the current QuickOPC build, 5.40.287.1. This build is now both on our download page, and on NuGet.

Can you please re-build your project with the new build.

Best regards

We have reproduced this problem. It is timing-related therefore somewhat unpredictable. We are working on a fix. I will post here when it is ready. Thank you for reporting it, and I apologize for the inconvenience.

Hello,

I understand this is not nice, because we have suggested to upgrade to a new version in order to overcome the other problem.

What you are now reporting comes from an area that has changed in version 5.40 (due to support for UA Alarms and Conditions), therefore it is possible that a problem has been introduced there. It has not come up in our testing, but we will re-test differently, and inspect the code now. If you can provide as much as possible information about what you do and in what timing sequence, it would be helpful (although you have already described a lot).

I still recommend switching over to version 5.40. This particular problem is something we can resolve - as soon as we get it reproduced. There won't be any, or any significant updates to version 5.35.

Best regards

Hi,

we've switched from 5.35 to 5.4 version for testing. We've used to nuget packages to get de dlls.
The code that worked before now sometimes throws an exception when we try to subscribe an item using SubscribeMonitoredItem. The error message is "Precondition failed: SdkMonitoredItem == null". The surprising thing is that first few items are subscribed ok. Then the next item throws an error but we get events for this item and the rest of items subscribe ok. Our code for now requires us to use SubscribeMonitoredItem in a loop but it worked without any errors for version 5.35. Even after we added a wait for 0.5 s between subscriptions we still sometimes get the error and it seems that it always throws it after two items. Can we manipulate some internal timeout to remedy that or do we have to redesign our code to use SubscribeMultipleItems ?

Regards,

Michal Waclawski

michal.waclawski@ukpowerreserve.com