adelynnb When I try to open it on StitchBuddy it says it can't open it because of a missing header. What does this mean and how do I fix it?
The error indicates an incorrect PES file format (which cannot be read by StitchBuddy), but the reasons are difficult to say for certain, at least without more information:
PNG files are pixel-based graphics, basically consisting of millions of dots with different colors, forming an image. A PES embroidery design is containing needle movements with a certain thread. As you can image, turning one into the other requires some sophisticated process, and I assume the program you used isn't fit for that purpose. Or - what happens from time to time - you have only renamed the file, changing its name extension from .png to .pes which is not a conversion of the file's content.
Which program did you use to convert the design? Feel free to forward the (assumed) PES file by mail, and I'll have a closer look: Maybe I can determine the true file format from its internal structure … although you might already be able to figure out what went wrong by the comment above.
