Some users may encounter issues attempting to install or uninstall Plex Media Server on Windows. Errors could also occur when trying to upgrade an existing installation. In many cases, this will manifest as a
0x80070643 error message.
Don't Remove Package Cache Install Files
Do not remove package cache installer files related to Plex Media Server. If you do so, you'll have trouble uninstalling or upgrading installations. Those files are found under...
...as well as:
Leave the content there alone to avoid issues.
Run the Microsoft Fix It
When encountering errors trying to install, uninstall, or upgrade on a Windows computer (such as an error that a
.msi file is missing), running the Microsoft Fix It will typically resolve the issue.
Related Page: Microsoft: Fix problems that programs cannot be installed or uninstalled
Receive 0x80070643 Error
You may see this error if the MSI software update registration has become corrupted or if the .NET Framework installation on the computer has become corrupted.
Typically, "Method 3" (steps 1 through 8) in the following Microsoft knowledge base article are appropriate when this error is encountered in relation to Plex Media Server.