This is about hyperref, see the discussion here:
You are using package "hyperref" and you have at least two pages "1".
==> recommended hyperref options: plainpages=false,pdfpagelabels
If the pages were labled differently , then the problem is solved.
A more detailed answer is here.
However, sometimes the error message becomes ...(name{XXX})..., i.e., something different from page numbering
It happens when you use {algorithmic} with hyperref: because each algorithm uses the same line-numbering scheme...
A solution is to fix the bug from {algorithmic} by using this small package together: \usepackage{algorithmic,algorithmic-fix}
It can be downloaded here (though not written by me!).