iTunes Store operation failed. Invalid Info.plist value. The value for the key 'NSExtensionPointIdentifier' in bundle /PlugIns/appname-safari-extension.appex is invalid.

I'm unable to upload my app to itunes connect to publish a new version. i'm getting this error.

iTunes Store operation failed. Invalid Info.plist value.
The value for the key 'NSExtensionPointIdentifier' in bundle /PlugIns/appname-safari-extension.appex is invalid.

Here is my share extension info.plist file, which looks normal.

<key>NSExtension</key>
  <dict>
       <key>NSExtensionPointIdentifier</key>
       <string>com.apple.share-services</string>
       <key>NSExtensionAttributes</key>
       <dict>
            <key>NSExtensionActivationRule</key>
            <dict>
                 <key>NSExtensionActivationSupportsAttachmentsWithMaxCount</key>
                 <integer>10</integer>
                 <key>NSExtensionActivationSupportsText</key>
                 <true/>
                 <key>NSExtensionActivationSupportsWebURLWithMaxCount</key>
                 <integer>10</integer>
            </dict>
       </dict>
       <key>NSExtensionMainStoryboard</key>
       <string>MainInterface</string>
  </dict>