the personal edition is unlimited, as long as you use documents created by yourself.
if you import document created by someone else, you only have 4 chances to do that, and everytime you import a document this way you'll have it with no data in it, so you need a reload.
After you finish all the 4 chances you can keep using the personal edition with your own documents, but you won't be able to open new files created by someone else.
