在使用c#打开powerpoint文档时，调用COM组件时返回了Error HRESULT E_FAIL

Trying to cope up with HRESULT E_FAIL error that I keep getting while trying to open a powerpoint file. There is more to code but the very basic operation for which I get the error is shown in the code block below. Reference DLLs being used are: Office 14.0.0 and Microsoft.Office.Interop.Powerpoint 14.0.0.Trying to cope up with HRESULT E_FAIL error tha