When I update to ConTeXt LMTX version 2021.03.20 01:07, the following happens during format generation:

tex error       > tex error on line 25 in file spac-hor.mkxl: Undefined control sequence

<line 3.25> \bitwiseflip \normalizelinemode \flattendiscretionariescode
   
<empty file>

So, what is happening here?

Jairo