Plesk and sites returns the error:
HTTP Error 500.21 - Internal Server Error Handler "StaticFile" has a bad module "StaticFileModule" in its module list
Wrong Modules order.
Please Make sure that all modules in IIS are in correct order as on the picture below:
To check it please go to IIS -> Server -> Modules and on the right panel click "View Ordered List". Then arrange them according to the example.