I am seeing this on a website that has been moved to a different folder on an IIS server:

Log Name: Application
Source: ASP.NET 4.0.30319.0
Date: 11/05/2018 12:13:36
Event ID: 1310
Task Category: Web Event
Level: Warning
Keywords: Classic
User: N/A
Computer: %COMPUTERNAME%.domain.suffix
Description:
Event code: 3008
Event message: A configuration error has occurred.
Event time: 11/05/2018 12:13:36
Event time (UTC): 11/05/2018 11:13:36
Event ID: 4fd8f4a189fe42b0990906e4a1098174
Event sequence: 34
Event occurrence: 1
Event detail code: 0

Application information:
Application domain: /LM/W3SVC/55/ROOT-1-131705103475489943
Trust level: Full
Application Virtual Path: /
Application Path: E:\Websites\www\websiteNAME\
Machine name: %COMPUTERNAME%

Process information:
Process ID: 10860
Process name: w3wp.exe
Account name: IIS APPPOOL\websiteNAME

Exception information:
Exception type: ConfigurationErrorsException
Exception message: It is an error to use a section registered as allowDefinition='MachineToApplication' beyond application level. This error can be caused by a virtual directory not being configured as an application in IIS. (E:\Websites\www\websiteNAME\gtme-forum\web.config line 29)
at System.Configuration.ConfigurationSchemaErrors.ThrowIfErrors(Boolean ignoreLocal)
at System.Configuration.BaseConfigurationRecord.ThrowIfParseErrors(ConfigurationSchemaErrors schemaErrors)
at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object& result, Object& resultRuntimeObject)
at System.Configuration.BaseConfigurationRecord.GetSection(String configKey)
at System.Web.Configuration.RuntimeConfig.GetSectionObject(String sectionName)
at System.Web.Configuration.RuntimeConfig.GetSection(String sectionName, Type type, ResultsIndex index)
at System.Web.Configuration.RuntimeConfig.get_Identity()
at System.Web.HttpContext.SetImpersonationEnabled()
at System.Web.HttpApplication.AssignContext(HttpContext context)
at System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context)



Request information:
http://personaltraine.rs/GTME-forum/ 
Request path: /GTME-forum/
User host address: 83.244.231.200
User:
Is authenticated: False
Authentication Type:
Thread account name: IIS APPPOOL\websiteNAME

Thread information:
Thread ID: 54
Thread account name: IIS APPPOOL\websiteNAME
Is impersonating: False
Stack trace: at System.Configuration.ConfigurationSchemaErrors.ThrowIfErrors(Boolean ignoreLocal)
at System.Configuration.BaseConfigurationRecord.ThrowIfParseErrors(ConfigurationSchemaErrors schemaErrors)
at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object& result, Object& resultRuntimeObject)
at System.Configuration.BaseConfigurationRecord.GetSection(String configKey)
at System.Web.Configuration.RuntimeConfig.GetSectionObject(String sectionName)
at System.Web.Configuration.RuntimeConfig.GetSection(String sectionName, Type type, ResultsIndex index)
at System.Web.Configuration.RuntimeConfig.get_Identity()
at System.Web.HttpContext.SetImpersonationEnabled()
at System.Web.HttpApplication.AssignContext(HttpContext context)
at System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context)


Custom event details:

Event Xml:



1310
3
3
0x80000000000000

2202997
Application
%COMPUTERNAME%.domain.suffix



3008
A configuration error has occurred.
11/05/2018 12:13:36
11/05/2018 11:13:36
4fd8f4a189fe42b0990906e4a1098174
34
1
0
/LM/W3SVC/55/ROOT-1-131705103475489943
Full
/
E:\Websites\www\websiteNAME\
%COMPUTERNAME%


10860
w3wp.exe
IIS APPPOOL\websiteNAME
ConfigurationErrorsException
It is an error to use a section registered as allowDefinition='MachineToApplication' beyond application level. This error can be caused by a virtual directory not being configured as an application in IIS. (E:\Websites\www\websiteNAME\gtme-forum\web.config line 29)
at System.Configuration.ConfigurationSchemaErrors.ThrowIfErrors(Boolean ignoreLocal)
at System.Configuration.BaseConfigurationRecord.ThrowIfParseErrors(ConfigurationSchemaErrors schemaErrors)
at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object& result, Object& resultRuntimeObject)
at System.Configuration.BaseConfigurationRecord.GetSection(String configKey)
at System.Web.Configuration.RuntimeConfig.GetSectionObject(String sectionName)
at System.Web.Configuration.RuntimeConfig.GetSection(String sectionName, Type type, ResultsIndex index)
at System.Web.Configuration.RuntimeConfig.get_Identity()
at System.Web.HttpContext.SetImpersonationEnabled()
at System.Web.HttpApplication.AssignContext(HttpContext context)
at System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context)


http://personaltraine.rs/GTME-forum/
/GTME-forum/
83.244.231.200


False


IIS APPPOOL\websiteNAME
54
IIS APPPOOL\websiteNAME
False
at System.Configuration.ConfigurationSchemaErrors.ThrowIfErrors(Boolean ignoreLocal)
at System.Configuration.BaseConfigurationRecord.ThrowIfParseErrors(ConfigurationSchemaErrors schemaErrors)
at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object& result, Object& resultRuntimeObject)
at System.Configuration.BaseConfigurationRecord.GetSection(String configKey)
at System.Web.Configuration.RuntimeConfig.GetSectionObject(String sectionName)
at System.Web.Configuration.RuntimeConfig.GetSection(String sectionName, Type type, ResultsIndex index)
at System.Web.Configuration.RuntimeConfig.get_Identity()
at System.Web.HttpContext.SetImpersonationEnabled()
at System.Web.HttpApplication.AssignContext(HttpContext context)
at System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context)

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This was an error with the old web.config file - the quick solution was to delete the application and recreate in the correct app pool.

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