My office is transitioning from Windows to Mac. Files which were created in Illustrator on the PC are showing up with images missing and their links broken. Same thing happens in reverse, if someone on a PC opens files made in Illustrator on the Mac the linked images will be unlinked for them. The images are stored on a central server and have not moved at all. What is causing this?
Sorry - before this gets closed as off-topic tech support - I've bee through this - it is the difference in how each OS expresses and reads filepaths, both symbolically as listed in the comment above and in how filepaths are parsed inside the OS - short answer is that there's no way round this - each time you jump OSes on the opening of the file, you'll need to repath if you want to see the images.
If you know, however, that one specific OS, "A"let's sayis the one which "matters" in that that's both where the designers live and where the files will reside when finally output, you can enact a policy in which folks on the other OS "B" don't repath when they make for example text-only edits, when the file's re-read into illustrator on OS "A", it shouldn't require repathing.
Hope that helps.
Link paths in all Adobe applications are absolute and not relative. Meaning they all reference the system they are on when initially creating the link. If the document moves, the absolute links break.
The only way to ensure links remain unbroken is to have all linked items on the same directory, and at the same hierarchy, as the working document and never work from a server.