[luatex] [LuaLaTex] Problems with Titlesec

[andrea del monaco]

Dear all,

since the last time I have upgraded my texlive distribution, I am
experiencing the following problem  at compilation-time:

! Missing number, treated as zero.
<to be read again>
\c@1
l.389 \section{Local in $\G$}\label{section:local_in_G}

The problem seems to be the titlesec package; in particular its behavior
with the primitive "\thesection", which appears to not store any number in
my case.
In fact, my .tex file include the following code

\titleformat{\section}[display]%
    {\SmallCaps\large}%
    {\Roman{\thesection}}%
    {1em}%
    {\centering}

and when I try to compile with

\titleformat{\section}[display]%
    {\SmallCaps\large}%
    {\Roman}%
    {1em}%
    {\centering}

namely without "thesection", everything runs perfectly.
I hereby specify that I am running texlive updated at its latest version
(i.e. 2016.41290-9) on Arch Linux, and LuaLaTex is 0.95.0.
I compile my .tex file simply launching "lualatex foo.tex" in my shell.

Do you have any suggestions/comments/remarks? If there exists, may you
advise me on any workaround? Maybe some luatex primitive that I can make
use of?

Thanks in advances!

Best,
andrea