Issue with PowerPivot start in Excel 2013

Hello!

We have the problem with PowerPivot start in Excel 2013:

"We couldn't load the Data Model. This may be because the Data Model in this workbook is damaged"

"PowerPivot is unable to load the Data Model".

We have Excel 2013 32-bit, PowerPivot 32-bit, running on Windows 7 OS 64-bit.

We have tried fix the issue with

1.http://blogs.technet.com/b/the_microsoft_excel_support_team_blog/archive/2013/08/27/powerpivot-for-excel-2013-error-when-opening-the-manage-window-quot-we-couldn-t-load-the-data-model-this-may-be-because-the-data-model-in-this-workgroup-is-damaged-quot.aspx

2. http://social.technet.microsoft.com/Forums/office/en-US/1df275c5-7e77-4bab-b025-c6f5bf1e25b2/excel-2013-powerpivot-error-powerpivot-is-unable-to-load-the-data-model?forum=excel

3.http://blogs.technet.com/b/the_microsoft_excel_support_team_blog/archive/2013/11/12/powerpivot-for-excel-2013-errors-after-october-update-kb-2825655.aspx

But we have the same problem now.

Could you help us please? What should we do for fixing the issue?

Best regards,

Oleksandr Nikolaienko