I have tried to delete the .vs , Binaries , Intermediate , Saved , .vsconfig , and .sln and then clicked generate and then opened the .sln with Jetbrains Rider to build the project but it still shows me that the built failed. I also tried to directly click into the project with Unreal Engine 5.41 but it seems like it just couldn’t open. It just kept giving me those error messages telling me to build from source. And then, I tried to find out the error by building the project from the compiler to see where’s the errors. I did solve some error that I accidentally made BUT there is an error/warning that I do not understand what it means at all.

Which is the one I highlighted in the RedisSerialiser.cs file

I tried to ask Microsoft copilot(ChatGPT alternative) after that, but I still do not get it. It told me to check Unreal Engine’s JSON deserialisation , verify input data or use Unreal Engine’s deserialisation methods but I did’t even know how to work with JSON and I’m not really sure what it is.

Can I know what I can do to solve the problem with “build failed” in my case ?