4.80 Installation 500 error when installing plugins

Using the 4.8 package without source code Windows instance and granting the IIS Apppool user Write permissions to the usual folders. Adding dot net 9 hosting and using a copy of a 4.5 istance database and a tempoary URL (not one listed in the stores) all seemed to go to plan until I tried to install any plugin. On restarting it throws a 500 error. Looking at the plugins.json file I can see the plugins listed in PluginNamesToInstall so it managed to reach this write phase before throwing the exception. Editing that back out and restarting recovers. Can anyone suggest what have I missed?

Just in case this had soimething to do with the temp URL I added a subdomain to the stores that is now being used for the site but the error remains.

Looks like one of the plugins you are trying to install is causing the issue. Can you turn on the file logging in web.config and check the log inside the Log folder? To turn it on please modify your web.config and set

stdoutLogEnabled="true" 

Thank you but it is not one but any plugin caused the error. I've tried one at a time and clearing out the changes in plugins.json after each failed attempt.
HTTP Error 500.30 - ASP.NET Core app failed to start
Common solutions to this issue:
The app failed to start
The app started but then stopped
The app started but threw an exception during startup
Troubleshooting steps:
Check the system event log for error messages
Enable logging the application process' stdout messages
Attach a debugger to the application process and inspect
For more guidance on diagnosing and handling these errors, visit Troubleshoot ASP.NET Core on Azure App Service and IIS.

It is an access denied situation. The "iis apppool\Nop48" user has write permission to the folder and that is the user for the IIS site. The .net CLR Version is set to No managed Code and the managed Pipilene mode is Integrated.

Then providing the read/write access to the root application directory for the user "iis apppool\Nop48" should solve the issue.

As stated at the outset that was done, but I must have missed something. Write permissions have now been granted to the IIS user all contents of folders App_Data, Plugins, Themes, wwwroot, plus the web.config fle.

RESOLVED

I went up a level to the root and granted write permission to iis apppool user and also IIS_IUSRS hoping this would overcome the issue albeit exposing the site. Tried again but still it failed.

Looking in the error log I can see that access to the plugins .deps.json file was denied. I think it also need Modify permission so I added that and it is sorted!

Off now to undo some of the additional permission I added and amend those that should be there to include modify.