Static files return Internal Server Error - iis

Question

I hosted a site called Paris on an IIS-server (Windows Server 2019), which have have 2 web applications
webParkingQueryApi
webParkingQueryApp
The file explorer path look like this:
Paris/ParkingQueryWebApi
Paris/ParkingQueryWebApp
Both application use the same AppPool, and both are .Net 4.6 Framework applications (one web API and one Web application).
AppPool: Name: Paris | Managed Pipeline: Integrated | .NET CLR version : 4.0 | Identity : {a service account in the AD}
Authentication Paris : anonymous. ParkingQueryWebApp : basic.
Problem: When I open webParkingQueryApp in browser all static files return "Internal Server Error".
Both applications work fine in my development server, but not in production.
I added permissions to the Service Account, DefaultAppPool, and Users so they can read, write and modify the Paris directory.
The Event Viewer throws an security warning when I refresh the site. It says : "A privileged service was called.", and it mentions Process Name: C:\Program Files\Google\Chrome\Application\chrome.exe. The security Id is my Windows account that I use to log into production.
EDIT
After I activated "Failed Request Tracing Rules" in IIS-manager and looked in the log files I found this error:
<RenderingInfo Culture="sv-SE">
<Opcode>MODULE_SET_RESPONSE_ERROR_STATUS</Opcode>
<Keywords>
<Keyword>RequestNotifications</Keyword>
</Keywords>
<freb:Description Data="Notification">AUTHENTICATE_REQUEST</freb:Description>
<freb:Description Data="ErrorCode">Either a required impersonation level was not provided, or the provided impersonation level is invalid.
(0x80070542)</freb:Description>
</RenderingInfo>
EDIT 2022-02-04
The static files return this information:
HTTP Error 500.0 | Module: IIS Web Core | Notification:
AuthenticateRequest | Handler: StaticFile | Error Code:0x80070542 |
Logon method: basic | Logon user: {my Windows account}.