Issue with Adobe Caslon Pro font in Indesign

I have been using Adobe Caslon Pro in Indesign on a book that i am currently designing. An issue started to come up where everytime I reopen the Id document, I would be welcomed with a window that says that the Font I was currently using was missing to which everytime I need to reactivate the font.

It is just quite irritating as ive tried to deactivate and reactivate the font but nothing changes the window that i recieve everytime I reopen the file.