I am unable to import my EAD file, what could the problem be?
Is the EAD valid? Import of EAD's which do not validate against the EAD 2002 DTD or Schema is not supported by the AT. You can check this using an xml editor, which will list any validation errors present.
Do you have any extremely long chunks of text? While many of the AT's fields accommodate large amounts of data (roughly 10,000 words) they do have a limit on space. Check to see if you have any notes or other elements which have very long values. You can test this by (temporarily) removing large chunks of text and then seeing if the EAD can be imported. If this is the source of the problem, you can try splitting long notes into parts so the text is spread across multiple fields.
Have you edited your EAD document in Microsoft word? Word can sometimes interject characters which aren't supported by standard XML processors. An example being smart or curly quotes, rather than straight quotes. If possible, it is best to use an XML editor for working with EAD files to avoid such problems.