VS2019無法載入專案The tool version "15.0"

4月 11, 2019

這兩天看到VS2019正式發佈後，馬上下載來試玩，未料一裝完打開專案後，還來不及開心就出現了無法載入專案錯誤...。

C:\projects\test.csproj : error : The tools version "15.0" is unrecognized. Available tools versions are "14.0", "2.0", "3.5", "4.0"

原因:

依測試結果，若是全新的OS安裝不會有問題，而原本筆電已有VS2017的才可能會發生。

搜尋相關文章後，錯誤訊息都指向了MsBuild相關的DLL在GAC等版本問題。在連串的測試及比對後，發現MsBuild相關的dll在全新OS安裝下只會有4.0及14.0。而我的筆電卻有15.1版本的dllGAC

解決方式:

用administrator 打開Visual Studio Developer Command

執行以下命令來移除Microsoft.Build.*.dll 15.1版本

gacutil.exe /u "Microsoft.Build.Framework, Version=15.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL"

gacutil.exe /u "Microsoft.Build, Version=15.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL"

gacutil.exe /u "Microsoft.Build.Utilities.Core, Version=15.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL"

gacutil.exe /u "Microsoft.Build.Engine, Version=15.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL"

gacutil.exe /u "Microsoft.Build.Tasks.Core, Version=15.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL"

開發社群的問題回報

https://developercommunity.visualstudio.com/content/problem/515088/cannot-open-any-project-in-visual-studio-2019-the.html

參考來源

https://forum.ncrunch.net/yaf_postst1819_Grid-Node--MSBuild-14-detection.aspx

https://developercommunity.visualstudio.com/content/problem/474337/generatecompiledependencycache-hash-settings-havin.html

https://stackoverflow.com/questions/45738512/could-not-load-type-microsoft-build-framework-sdkreference-on-project-open-in

https://developercommunity.visualstudio.com/content/problem/311136/update-to-1580-projects-wont-load.html