Office Web Applications 2013 - Unhealthy farm; Excel Calculation Services failed to convert the following file: http://internal/ecsxlstest.xls

Hello!

I have a fresh deployment of Office Web Applications 2013.

I ran New-OfficeWebFarm with following arguments:

New-OfficeWebAppsFarm-InternalURLhttps://the.internal.url-ExternalURLhttps://the.public.url-AllowCEIP:$false-AllowHttp:$false-CacheLocation"D:\Cache"-CacheSizeInGB30-CertificateName"<the certificate fridenly name>"-ClipartEnabled:$true-EditingEnabled:$true-LogLocation"D:\Logs"-LogVerbosity"Unexpected"-MaxMemoryCacheSizeInMB8192-OpenFromUncEnabled:$true-OpenFromUrlEnabled:$true-Proxyhttp://the.proxy.url-RenderingLocalCacheLocation"D:\Rendering Cache"-SSLOffloaded:$false-TranslationEnabled:$true

It ran OK, I can see the discovery XML. 

Ever since then, an warning and several errors are logged in the event viewer:

Excel Web App, warning, ID 7914:

Excel Calculation Services failed to convert the following file: http://internal/ecsxlstest.xls

Office Web Apps Monitoring, error, ID 1043:

<?xml version="1.0" encoding="utf-16"?><HealthReport xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><HealthMessage>ExcelServicesEcsWatchdog reported status for ExcelServicesEcs in category 'EntireService'. Reported status: ECS watchdog test failed. Got CommunicationException System.ServiceModel.FaultException`1[Microsoft.Office.Excel.Server.ExcelServerMessage]: We couldn't open this workbook in the browser. (Fault Detail is equal to Microsoft.Office.Excel.Server.ExcelServerMessage).</HealthMessage></HealthReport>

<?xml version="1.0" encoding="utf-16"?><HealthReport xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><HealthMessage>ExcelServicesEcsWatchdog reported status for ExcelServicesEcs in category 'EntireService'. Reported status: ECS watchdog test failed. Got CommunicationException System.ServiceModel.FaultException`1[Microsoft.Office.Excel.Server.ExcelServerMessage]: We couldn't open this workbook in the browser. (Fault Detail is equal to Microsoft.Office.Excel.Server.ExcelServerMessage).</HealthMessage></HealthReport>

I connected Office Web Apps with Sharepoint 2013, the conenction is OK, the zones match, the integration is alive, but I can't open any document in the web apps.

I made a repair, reconfigured the office wep apps farm, and now it have following configuration:

PS C:\Windows\system32> Get-OfficeWebAppsFarm


FarmOU                            :
InternalURL                       : http://theserver/
ExternalURL                       : https://the.external.url/
AllowHTTP                         : True
SSLOffloaded                      : True
CertificateName                   : the friendly name
EditingEnabled                    : True
LogLocation                       : D:\Logs
LogRetentionInDays                : 7
LogVerbosity                      : VerboseEx
Proxy                             : http://the.proxy.server/
CacheLocation                     : D:\Cache
MaxMemoryCacheSizeInMB            : 8192
DocumentInfoCacheSize             : 5000
CacheSizeInGB                     : 30
ClipartEnabled                    : True
TranslationEnabled                : True
MaxTranslationCharacterCount      : 125000
TranslationServiceAppId           :
TranslationServiceAddress         :
RenderingLocalCacheLocation       : D:\Rendering Cache
RecycleActiveProcessCount         : 5
AllowCEIP                         : False
ExcelRequestDurationMax           : 300
ExcelSessionTimeout               : 450
ExcelWorkbookSizeMax              : 10
ExcelPrivateBytesMax              : -1
ExcelConnectionLifetime           : 1800
ExcelExternalDataCacheLifetime    : 300
ExcelAllowExternalData            : True
ExcelWarnOnDataRefresh            : True
OpenFromUrlEnabled                : True
OpenFromUncEnabled                : True
OpenFromUrlThrottlingEnabled      : True
PicturePasteDisabled              : False
RemovePersonalInformationFromLogs : False
AllowHttpSecureStoreConnections   : False
Machines                          : {theserver}

The error remains. I tested manually to open the ecsxlstest.xls file, and it doesn't open indeed. Any xlsx file opens OK, but any xls file - does not.

The machine is reported "unhealthy", I guess, because of the error:

PS C:\Windows\system32> Get-OfficeWebAppsMachine

MasterMachineName                              MachineName                                   Roles                                                                          HealthStatus
-----------------                              -----------                                   -----                                                                          ------------
THESERVER                                         THESERVER                                        {All}                                                                             Unhealthy

What can I do, to make the farm "healthy"? And what I need to do, to be able to open Excel 2003 files in web apps?