How do I fix error code cs1056: Unexpected Character

After updating some of my projects from 2018 to 2019.3.13f1 I have been experiencing the above error in the updated projects and ones that I made in 2019 using the hub. With the updated ones the editor claims that either attached scripts are missing or there is a compiler error but within visual studio there is no compiler errors and reimporting scripts doesn’t work either. I have attached screenshots

Delete every folder in the project root except Assets and Project Settings, then let Unity re-import the entire project again slowly.

If issues still show up, you might have assets within the project which haven’t been updated to support Unity 2019 (Typically, missing dependencies, the use of new Package Manager in 2019 which is missing in 2018 if I’m correct). In that case, you’ll need to manually open your project with Unity 2018 and update every asset/plugin to the latest versions before re-importing with 2019 using the aforementioned steps.