Hi Louise,
We have checked the file at our end and did not encounter any issues with the file. Since the above-file is a vector file, it will work the best with Illustrator, so I would suggest you to open it with Illustrator, not with Photoshop since Photoshop doesn’t manage vectors properly(in Photoshop the Ai file becomes rasters).
However, if you do not have Illustrator, rather than subscribing the app you can always use the 7 day trial version(in order to use the vector file you have downloaded from Adobe Stock).
You may use this link to download the trial version of Illustrator: Download a free trial or buy Adobe products | Adobe free trials & downloads
Feel free to update this thread in case of any additional questions.
Regards,
Twarita