Hi Gabrielle!
I would let Company B know that you need the original .story source file. It sounds like maybe they published the output and sent you the zipped version!
Does the content in the zipped folder look like this?
If so, they sent you a published course that does not have anything you can edit in. Ask the designer at Company B to open up Storyline, do a fresh "Save As" and save the file to their desktop, and have them email you that file. The extension will be whatever the name of the file is followed by ".story" -- Similar to if you needed someone to send you a PowerPoint or Word document, you just need the actual file they were working on!
Sometimes these files can be REALLY big depending on how much multimedia is in them. If their email server won't allow them to send a file that big, WeTransfer.com is free way to share large files.
