Dear SDL,

During testing our plugin a strange error occoured, while the application called GetSourceLanguageFiles() on a FilesBasedProject. Exception message is inserted below.

It occours when you create a new Project, add a file for translating (in my case a word file), add a file as reference (I added a xls file and changed the usage). 

How this exception could be avoided?

Thanks in advance

Balazs

<ErrorMessage>Unable to cast object of type 'Sdl.ProjectApi.Implementation.ReferenceFile' to type 'Sdl.ProjectApi.ITranslatableFile'.</ErrorMessage>

<Exception>
<Type>System.InvalidCastException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</Type>
<HelpLink />
<Source>Sdl.ProjectAutomation.FileBased</Source>
<HResult>-2147467262</HResult>
<StackTrace><![CDATA[ at Sdl.ProjectAutomation.FileBased.FileBasedProject.CreateProjectFileObject(ILanguageFile languageFile)
at Sdl.ProjectAutomation.FileBased.FileBasedProject.GetLanguageFilesCore(Language language)
at Sdl.ProjectAutomation.FileBased.FileBasedProject.GetSourceLanguageFiles()