Adobe Captivate - Shared from another Developer

Hi!

A couple of people on our team are working on developing an elearning module, so we need to share the file with each other (e.g., One person adds content then sends it to another person to add a different section).

However, when we share the file, the recipient can't open it.

A coworker sent me a file via google drive, I downloaded it, and when I tried to open it, I got this message:

Adobe Captivate could not open "(filename)". Ensure that:

-The file is not open already.

-The file is not damaged. For example, if the file was an email attachment, ensure that you have decoded the file correctly.

-The hard disk has sufficient available space.

-The system has sufficient resources. To optimize the resources, close all the other open applications.

We both have Adobe Captivate 9. He also tried putting the file on a shared drive. When I downloaded it and then tried to open it, I received the same error.

Is there anything we're doing wrong? We both have to work on this file, and I didn't anticipate having difficulty working on a project file with another developer.

Thanks!