Error message - server dll

I continue to get an error message when I try to run the app.

The message say cannot copy obj\Debug\netcoreapp2.0\server.dll to bin\Debug\netcoreapp2.0\server.dll. See the exact error message at the end of this post.

I mentioned this in an earlier post and had decided it my workflow. However, I have become more convinced this is not the case.

I like to make changes and then check the page to make sure it is rendering the desired result. I do that many times a day. I find when I Run the app the Stop button is not an option I am presented with. Closing RadZen does release the file so it can be used. So no Stop and Closing/Restarting RadZen does help. The only solution I have found is to Restart the pc, which is not something I believe should happen.

I think the IDE should be a bit more refined in closing and opening the needed .dlls. \

Just my opinion.


John W


dotnet: C:\Program Files\dotnet\sdk\2.1.4\Microsoft.Common.CurrentVersion.targets(4106,5): error MSB3027: Could not copy “obj\Debug\netcoreapp2.0\server.dll” to “bin\Debug\netcoreapp2.0\server.dll”. Exceeded retry count of 10. Failed. [D:\jkwrp\Documents\Solomon\server\project.vbproj]
C:\Program Files\dotnet\sdk\2.1.4\Microsoft.Common.CurrentVersion.targets(4106,5): error MSB3021: Unable to copy file “obj\Debug\netcoreapp2.0\server.dll” to “bin\Debug\netcoreapp2.0\server.dll”. The process cannot access the file ‘D:\jkwrp\Documents\Solomon\server\bin\Debug\netcoreapp2.0\server.dll’ because it is being used by another process. [D:\jkwrp\Documents\Solomon\server\project.vbproj]


dotnet: The build failed. Please fix the build errors and run again.

@John_Willems are you running some anti virus software? Radzen itself doesn’t lock any dll files but uses the .NET CLI tools to build and run applications. Although some people have reported this error before we have been unable to reproduce it. Looking online we found people complaining about the same issue and it turned out some antiviral software was locking those files. Could that be the case here?

This covers the issue

server.dll locking

Thanks for posts

@Radzen - it appears to me that there are enough reports of this running on a variety of systems it is an issue/bug. Whether its and MS bug or in Radzen itself I cannot say. The only consistent thing in this RadZen not releasing the Core2.0 server.dll. Rebooting/restarting the pc does seem the correct way to deal with this.

I do use MS Defender for my anti-virus. I have not had a problem with it and any of the other development platforms use.

@Alistair- Thanks for the link, I will give it a try when it next happens. If it works its better than a restart!

Hi John,

We will do our best to find what’s causing this and to fix or workaround it! For sure you do not need to restart you machine, you can execute the following command in your command prompt:

taskkill /f /im dotnet.exe

Best Regards,

Thank you for the command to kill the process.

John W