When entering data the system will not allow me to save my work.

This may be due to mandatory fields that are left blank before you hit save. 

All mandatory, starred, fields need to have some form of text in them before you navigate away from the page.  You can simply add a single letter or word as a work around and return to complete it again later if necessary.  This approach however is not without risk as the field will be considered complete by the system and the 'check' not effective.  It is important that you note which area you need to return to and complete at a later time.  Page 5 of the downloadable guide has further advice.

We recommend clicking the check saved project button on the left of your screen before saving and exiting.