It seems like you're facing compilation errors in your client-side csproj. Here are a few steps you can try to resolve the issue:
1. Make sure you have the necessary NuGet packages installed. You can check this by opening the NuGet Package Manager and verifying that all required packages are installed.
2. Clean and rebuild your solution. Right-click on the solution in Visual Studio, select 'Clean Solution', and then select 'Rebuild Solution'. This will ensure that all the necessary files are built correctly.
3. Check the references in your csproj file. Make sure that all required references are included and properly configured. If any references are missing or incorrect, update them accordingly.
4. Double-check your project file structure. Ensure that all necessary files and folders are present and correctly placed in your project directory.
If these steps don't resolve your issue, you might need to provide more information about the specific errors you're encountering, such as the error messages and stack traces. This will help in identifying the root cause of the problem.