Installation issues with linksync eParcel for Magento

1. Labels and or Manifest Summary PDF links give a 404 error or blank page

This usually is the result of either or both of the following: 

1. the content of the linksync extension have not been properly copied over to your server - in particular, the those contained in the 'media' directory.
2. the permission on the linksync folders in the media directory aren't correct. The following folders should be set to 775 recursively: 
    

/media/linksync/label/consignment/
/media/linksync/label/manifest/
/media/linksync/label/returnlabels/

After you check/correct the above to points, flush the Magento cache and try to create a new consignment and manifest and see if the PDF files save correctly.