Does a box in 13 have to be checked? No boxes are checked on my W-2 and turbo tax will not let me continue

It is very common for there not to be a checkmark in any of the checkboxes for Box 13 in a Form W-2.

When you say it will not let you continue, is there an error message that mentions box 13? or does it highlight that section?

If there is a Code in Box 12 for a retirement plan, it may be looking for that to be checked in Box 13. 

If you have error messages to fix entries on this particular page and you have "copied and pasted" to enter some of the information, it might have spaces or other invisible formatting characters that are causing the errors.  Please be sure there are no extra spaces before the entries or after the entries.  If you imported the document, please delete and try reentering manually.  Also, be sure there are no zeros listed. If the box is blank, please leave it blank.

If this does not completely solve the problem, please let us know more details, so we may better assist you.