From Günter [1]:
the difference is the textcommand for ETB which changed from
{\ascii\ETB} to
0x21a8 "\\ETB" "ascii" "force=utf8" # UP DOWN
ARROW WITH BASE
because the former resulted in
l.513 \ascii
\ETB{}
! Undefined control sequence.
[1]
https://www.mail-archive.com/search?l=mid&q=nr48qn%242gb%241%40blaine.gmane.org
\begin_layout Standard
\size normal
-from package "ascii" and "ifsym": ®↨◻◼ ◙ ◙
+from package "ascii" and "ifsym": ®
+\begin_inset ERT
+status collapsed
+
+\begin_layout Plain Layout
+{
+\backslash
+ascii
+\backslash
+ETB}
+\end_layout
+
+\end_inset
+
+◻◼ ◙ ◙
\end_layout
\begin_layout Standard