Solution One: How Can You Resolve 815 error Error Manually?
To repair 815 error error safely and fast, we highly recommend you to do a free check with sfc utility.
1. To do this, click Start, type Command Prompt or cmd in the Search box, right-click Command Prompt, and then click Run as administrator. If you are prompted for an administrator password or for a confirmation, type the password, or click Allow.
2. At the command prompt, type the following command, and then press ENTER: