Use AppCMD to change Request Filtering extensions

Go to Inetmgr > ServerName > Request Filtering > Filename extensions.  You can see all blocked extensions.

Open a command prompt and type

‘To allow
c:windowssystem32inetsrvappcmd set config
/section:system.webServer/security/requestFiltering -fileExtensions.[fileExtension=’.csproj’].allowed:true

‘To deny
c:windowssystem32inetsrvappcmd set config
/section:system.webServer/security/requestFiltering -fileExtensions.[fileExtension=’.csproj’].allowed:false

‘List all properties.
appcmd set config /section:system.webServer/security/requestFiltering -?
ERROR ( message:-allowDoubleEscaping
-allowHighBitCharacters
-fileExtensions.allowUnlisted
-fileExtensions.applyToWebDAV
-fileExtensions.[fileExtension=’string’].fileExtension
-fileExtensions.[fileExtension=’string’].allowed
-requestLimits.maxAllowedContentLength
-requestLimits.maxUrl
-requestLimits.maxQueryString
-requestLimits.headerLimits.[header=’string’].header
-requestLimits.headerLimits.[header=’string’].sizeLimit
-verbs.allowUnlisted
-verbs.applyToWebDAV
-verbs.[verb=’string’].verb
-verbs.[verb=’string’].allowed
-hiddenSegments.applyToWebDAV
-hiddenSegments.[segment=’string’].segment
-denyUrlSequences.[sequence=’string’].sequence
 )