It is a hardcoded error and already described in Archiving FI Transaction Figures (FI-GL, FI-AR, FI-AP) - Financial Accounting (FI) - SAP Library
that you cannot archive any data for current and previous and future periods.
This is probably a safety measure. Just imagine that you are not automatically done with the previous year, it is quite usual for year end activities that you post to the last year while you already in the new year, which also means that you have not yet created the final balance sheet for the previous year.
It is probably not possible for the archiving program to know if the previous year got finally closed.