Problems with Managed Metadata Column in SharePoint 2013

Hello together,

I got an issue with the managed metadata column in SharePoint 2013. I have created site columns of type "TaxonomyFieldType" to include it into a content type and list. During deployment I got the following exception:

Returning error with exception information. Type: App, Source: AppWeb, Detail: There was a problem with activating the app web definition., Correlation: a8d97b01-0b52-493e-ab8f-8cef9d83e1e2, Exception: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.InvalidCastException: Unable to cast object of type 'System.Xml.XmlNode[]' to type 'System.String'.   
 at Microsoft.SharePoint.Taxonomy.TaxonomyField.SetProperties()   
 at Microsoft.SharePoint.Taxonomy.TaxonomyField.Initialize(SPFieldCollection fields)   
 at Microsoft.SharePoint.Taxonomy.TaxonomyField..ctor(SPFieldCollection fields, String fieldName) 

I tried most changes documented in the web and boards, but nothing helped me out. So I belive I have done a small mistake, which I am currently not able to see. Maybe someone got the same issue and can tell me what I did wrong.

Here is my Site Column Definition:

<?xml version="1.0" encoding="utf-8"?><Elements xmlns="http://schemas.microsoft.com/sharepoint/"><Field
       ID="{9c18402b-4c29-4dcc-99b5-addc21b613cc}"
       Name="GHInvolvedDepartmentsIT"
       DisplayName="$Resources:InvolvedDepartmentsIT;"
       Type="TaxonomyFieldType"
       List="{160cf4b8-8ae5-4429-9e3d-aad3333396c5}"
       ShowField="Term$Resources:core,Language;"
       Required="FALSE"
       EnforceUniqueValues="FALSE"
       Group="$Resources:ContentGroupName;"><Customization><ArrayOfProperty><Property><Name>TextField</Name><Value xmlns:q6="http://www.w3.org/2001/XMLSchema" p4:type="q6:string" xmlns:p4="http://www.w3.org/2001/XMLSchema-instance">aaf9ff4f-29b4-453c-a125-b39c1D205bd5</Value></Property></ArrayOfProperty></Customization></Field><Field
       ID="{aaf9ff4f-29b4-453c-a125-b39c1D205bd5}"
       Name="InvolvedDepartmentsITTax"
       DisplayName="InvolvedDepartmentsITTax"
       Type="Note"
       Hidden="TRUE"
       Required="FALSE"
       ShowInViewForms="FALSE"
       Group="$Resources:ContentGroupName;"></Field></Elements>