[tex-live] BibLatex issues after last upgrade

[Angelo Graziosi]

This morning I did a TL-2015 upgrade but some documents do not build any 
more. For example:

$ latexmk -pdf solutio_majorana
[...]
(/opt/texlive/texmf-dist/tex/latex/biblatex/bbx/authoryear.bbx
(/opt/texlive/texmf-dist/tex/latex/biblatex/bbx/standard.bbx))
(/opt/texlive/texmf-dist/tex/latex/biblatex-philosophy/philosophy-standard.bbx
! Undefined control sequence.
l.1597 \ifblx at load@version at one

?

? h
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

?
...

Notice the same document built fine with TL-2015 upgrade I did on March 
01...


   Angelo