Extension Manager CC failed to install extension

Hi All,

When I try to install my extension then it shows me folllowing error message dialog.

I am on WIndows 7 (64-bit) and having both versions of InDesign CC(32 and 64) installed

I have downloaded extension manager from http://www.adobe.com/exchange/em_download/

While I tested the same extension on another windows machine which have both InDesign CC versions installed then got following error message.

"The extension XXXX does not contain a valid signature.

The extension will not be installed."

Please help me to fix the problem.

Regards,

Alam