How do I fix a "failed to open file at location" error? Specifically a video file

My command is the following:

./build/bin/FaceLandmarkVid -f "./samples/default.wmv"

I am trying to run a tool on a video stored in samples folder. It gives me the following error:

Failed to open the video file at location: ./samples/default.wmv

How can I go about fixing this?

I'd be more than happy to answer further questions if required. Thank you.

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