This issue can be caused by a corrupted state of the .Net framework that currently exists on your computer. This can be caused for various reasons to include but not limited to: other applications overwriting .net files, viruses and corrupt hard drive
To troubleshoot this issue you will need to uninstall multiple versions of the .net framework using a .net cleanup utility, and then reinstall those versions in their correct order.
I would suggest you to follow the steps in the link below in order to resolve this issue.
I: When installing .Net Framework updates using Windows update or Microsoft Update you may receive Error 0x643 or 0x80070643