I get this error when i create a project. I tried reinstalling unity but this didn't fix anything. Anyone know how to resolve this error?

A very fast google search showed me this:

Go to Preferences

Select GI Cache tab

Enable and Set custom cache location

You could also :

Try to uninstall Unity 5.3 and remove from the Windows Registry the Entry HKEY_CURRENT_USER\SOFTWARE\Unity Technologies

And then reinstall!