Terminating Old Web Drivers
Any time your automation exits on an error it will leave its drivers running, and those will prevent your project from being able to build successfully.
You can terminate old drivers by opening Powershell and running the following script:
Stop-Process -Name "chromedriver" -Force
You can change "chromedriver" to whichever drivers you have been running (edgedriver, firefoxdriver, etc).
Thanks to Chayston for this nugget of wisdom!