# Error message **URL:** \ **Category:** Angular\ **Created:** [May 1, 2018, 8:32pm UTC](https://forum.radzen.com/t/error-message/325 "2018-05-01T20:32:35Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![John\_Willems](https://forum.radzen.com/user_avatar/forum.radzen.com/john_willems/32/1298_2.png) [@John\_Willems](https://forum.radzen.com/u/John_Willems)\ **Post date:** [May 1, 2018, 8:32pm UTC](https://forum.radzen.com/t/error-message/325/1 "2018-05-01T20:32:35Z")
I am using the RadZen trial. When I first run my test application all goes smoothly However, when make changes and run it again I get this error. The application does not run. I don’t know if this is a bug or developer error. Suggestions? dotnet: C:\Program Files\dotnet\sdk\2.1.4\Microsoft.Common.CurrentVersion.targets(4106,5): warning MSB3026: Could not copy “obj\Debug\netcoreapp2.0\server.dll” to “bin\Debug\netcoreapp2.0\server.dll” ---
**Author:** ![enchev](https://forum.radzen.com/user_avatar/forum.radzen.com/enchev/32/16_2.png) [@enchev](https://forum.radzen.com/u/enchev)\ **Post date:** [May 2, 2018, 5:16am UTC](https://forum.radzen.com/t/error-message/325/2 "2018-05-02T05:16:54Z")
Hi John, It seems that the sever,dll is locked by a process for some reason. Can you try to exit the app in Radzen (go to all applications screen), open the app and run it again? Best Regards, Vladimir ---
**Author:** ![ThomasS](https://forum.radzen.com/letter_avatar_proxy/v4/letter/t/ba9def/32.png) [@ThomasS](https://forum.radzen.com/u/ThomasS)\ **Post date:** [May 2, 2018, 12:16pm UTC](https://forum.radzen.com/t/error-message/325/3 "2018-05-02T12:16:15Z")
Kill the “dotnet” Task in Taskmanager will help. For some reason the dotnet process doesnt close for around 50% of all the time. it’s bothering and if anybody finds out how to get rid of this… let me know! 🙂 Thomas ---
**Author:** ![John\_Willems](https://forum.radzen.com/user_avatar/forum.radzen.com/john_willems/32/1298_2.png) [@John\_Willems](https://forum.radzen.com/u/John_Willems)\ **Post date:** [May 2, 2018, 12:58pm UTC](https://forum.radzen.com/t/error-message/325/4 "2018-05-02T12:58:40Z")
Vladimir - I have done that, closing and reopening it does not work. The only way I have found is to restart the dev pc. That really slows up the work process. Perhaps a fix… Thomas - thanks I will try that next. Hopefully RadZen will find a more elegant solution in the days to come. I appreciate the suggestions and help. John W. ---
**Author:** ![korchev](https://forum.radzen.com/user_avatar/forum.radzen.com/korchev/32/4_2.png) [@korchev](https://forum.radzen.com/u/korchev)\ **Post date:** [May 2, 2018, 1:13pm UTC](https://forum.radzen.com/t/error-message/325/5 "2018-05-02T13:13:41Z")
Do you stop the application before making changes or not? Also are those changes? Honestly we haven’t got the locking error to appear very often let alone 50% of the times. We would appreciate some steps that predictably reproduce the locking so we can troubleshoot at our side. ---
**Author:** ![John\_Willems](https://forum.radzen.com/user_avatar/forum.radzen.com/john_willems/32/1298_2.png) [@John\_Willems](https://forum.radzen.com/u/John_Willems)\ **Post date:** [May 2, 2018, 2:17pm UTC](https://forum.radzen.com/t/error-message/325/6 "2018-05-02T14:17:43Z")
I was not stopping the app first. I was simply closing the browser. As I recall the button goes from Stop back to Run which I assume also re-compiles the app. As it stands now. (My steps) I open RadZen I open my test app I make changes to a page I run the app The first time I run the app it works as expected. I close the browser Make changes to the page Use the Run button I now get the error 100% of the time I reboot the pc It runs the first time and errors after that. Hope this helps. ---
**Author:** ![John\_Willems](https://forum.radzen.com/user_avatar/forum.radzen.com/john_willems/32/1298_2.png) [@John\_Willems](https://forum.radzen.com/u/John_Willems)\ **Post date:** [May 2, 2018, 4:33pm UTC](https://forum.radzen.com/t/error-message/325/7 "2018-05-02T16:33:17Z")
It appears to be a workflow issue on my part. I tried closing the browser and then the Stop button. That seems to be the solution, at least for now. If the error comes back I will update the thread… Thanks to everyone!