no preview, cant open document (office web apps 2013)

I downloaded the office web apps

no document preview of office documents.
there is a preview of websites and jpg files.

Get-SPWOPIBinding (on the sharepoint server)
servername.domain.com is the WAC server.

When installing: 
Office web apps server:
Add-WindowsFeature Web-Server,Web-Mgmt-Tools,Web-Mgmt-Console,Web-WebServer,Web-Common-Http,Web-Default-Doc,Web-Static-Content,Web-Performance,Web-Stat-Compression,Web-Dyn-Compression,Web-Security,Web-Filtering,Web-Windows-Auth,Web-App-Dev,Web-Net-Ext45,Web-Asp-Net45,Web-ISAPI-Ext,Web-ISAPI-Filter,Web-Includes,InkandHandwritingServices
New-OfficeWebAppsFarm -InternalUrl "http://wac" -EditingEnabled
dism /online /enable-feature /featurename:IIS-ASPNET45

Notice I have http://wac in New-OfficeWebAppsFarm

Sharepoint server:
New-SPWOPIBinding -ServerName servername.domain.com -allowHTTP
Get-SPWOPIZone


Application     : Excel
Extension       : ODS
ProgId          : 
Action          : view
IsDefaultAction : True
ServerName      : Servername.domain.com
WopiZone        : internal-http

Application     : Excel
Extension       : XLS
ProgId          : 
Action          : view
IsDefaultAction : True
ServerName      : Servername.domain.com
WopiZone        : internal-http

Application     : Excel
Extension       : XLSB
ProgId          : 
Action          : view
IsDefaultAction : True
ServerName      : Servername.domain.com
WopiZone        : internal-http

Application     : Excel
Extension       : XLSM
ProgId          : 
Action          : view
IsDefaultAction : True
ServerName      : Servername.domain.com
WopiZone        : internal-http

Application     : Excel
Extension       : XLSX
ProgId          : 
Action          : view
IsDefaultAction : True
ServerName      : Servername.domain.com
WopiZone        : internal-http

Application     : Excel
Extension       : ODS
ProgId          : 
Action          : edit
IsDefaultAction : False
ServerName      : Servername.domain.com
WopiZone        : internal-http

Application     : Excel
Extension       : XLSB
ProgId          : 
Action          : edit
IsDefaultAction : False
ServerName      : Servername.domain.com
WopiZone        : internal-http
 
and many more...

on the WAC server this is the configuration like it was
FarmOU                          :
InternalURL                     : http://wac
ExternalURL                     :
AllowHTTP                       : True
SSLOffloaded                    : False
CertificateName                 :
EditingEnabled                  : True
LogLocation                     : C:\ProgramData\Microsoft\OfficeWebApps\Data\Logs\ULS
LogRetentionInDays              : 7
LogVerbosity                    :
Proxy                           :
CacheLocation                   : C:\ProgramData\Microsoft\OfficeWebApps\Working\d
MaxMemoryCacheSizeInMB          : 75
DocumentInfoCacheSize           : 5000
CacheSizeInGB                   : 15
ClipartEnabled                  : False
TranslationEnabled              : False
MaxTranslationCharacterCount    : 125000
TranslationServiceAppId         :
TranslationServiceAddress       :
RenderingLocalCacheLocation     : C:\ProgramData\Microsoft\OfficeWebApps\Working\waccache
RecycleActiveProcessCount       : 5
AllowCEIP                       : False
ExcelRequestDurationMax         : 300
ExcelSessionTimeout             : 450
ExcelWorkbookSizeMax            : 10
ExcelPrivateBytesMax            : -1
ExcelConnectionLifetime         : 1800
ExcelExternalDataCacheLifetime  : 300
ExcelAllowExternalData          : True
ExcelWarnOnDataRefresh          : True
OpenFromUrlEnabled              : False
OpenFromUncEnabled              : True
OpenFromUrlThrottlingEnabled    : True
AllowHttpSecureStoreConnections : False
Machines                        : {Servername}

Then I changed the InternalUrl from wac to the servername.domain.com

stopped the sharepoint timer and cleared the config cache.

The errors I am getting in the Sharepoint log:
w3wp.exe (0x0E44)                      0x33B0 SharePoint Foundation         Runtime                      tkauUnexpectedSystem.ArgumentException: The Ribbon Tab with id: "Ribbon.Read" has not been made available for this page or does not exist. Use Ribbon.MakeTabAvailable().    at Microsoft.Web.CommandUI.Ribbon.Render(HtmlTextWriter writer)    at Microsoft.SharePoint.WebControls.SPRibbon.Render(HtmlTextWriter writer)     at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)     at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)     at Microsoft.SharePoint.WebControls.AjaxDelta.RenderChildren(HtmlTextWriter output)     at System.Web.UI.WebControls.WebControl.RenderContents(HtmlTextWriter writer)     at System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer)     at Microsoft.SharePoint.WebControls.AjaxDelta.Render(Ht...c959199c-e55d-20aa-7511-81e1a00e753d
w3wp.exe (0x0E44)                      0x33B0 SharePoint Foundation         Runtime                      tkauUnexpected...mlTextWriter writer)     at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)     at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)     at System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer)     at System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer)     at Microsoft.SharePoint.WebControls.SharePointForm.Render(HtmlTextWriter output)     at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)     at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)     at System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer)     at System.Web.UI.Control.RenderControlInternal(Ht...c959199c-e55d-20aa-7511-81e1a00e753d
w3wp.exe (0x0E44)                      0x33B0 SharePoint Foundation         Runtime                      tkauUnexpected...mlTextWriter writer, ControlAdapter adapter)     at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)     at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)     at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)     at System.Web.UI.Page.Render(HtmlTextWriter writer)     at Microsoft.SharePoint.WebControls.DeltaPage.RenderToBase(HtmlTextWriter writer)     at Microsoft.SharePoint.WebControls.DeltaPage.Render(HtmlTextWriter writer)     at Microsoft.SharePoint.WebPartPages.WikiEditPage.Render(HtmlTextWriter writer)     at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)     at System.Web.UI.Page.ProcessRequestMain(Boolean includ...c959199c-e55d-20aa-7511-81e1a00e753d
w3wp.exe (0x0E44)                      0x33B0 SharePoint Foundation         Runtime                      tkauUnexpected...eStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)c959199c-e55d-20aa-7511-81e1a00e753d

I ran
$config = (Get-SPSecurityTokenServiceConfig)
$config.AllowOAuthOverHttp = $true
$config.Update()
It didnt help.

Can I ask for a step by step guidance of what I need to do?
No preview of documents, does not open in browser.

best regards,
Olafur