HDRP not working in 2019.2

After I chose the HDRP in a new project's template the project then appeared to have a bunch of errors involving some scripts (Legacy DoF, etc) and packages' manifest.json. I couldn't choose the HDRP as the render pipeline, so, of course, the materials in the sample scene appeared pink. I then deleted the manifest.json and the HDRP asset completely disappeared from my project. I then wasn't able to locate it in the Package Manager window. Has this happened to anyone else? If so, how did you solve the problem?

My Unity version is 2019.2.0a13, OS is Windows 7, 64-bit.