I’m trying to export all my agenda files into an ics file via org-icalendar-combine-agenda-files. However, the export process stops halfway through. The following are shown in Messages:

org-babel-exp process emacs-lisp at line 72...
org-babel-exp process emacs-lisp at line 208...
user-error: No language for src block: (unnamed)
which is weird because

I already set org-calendar-include-body to nil. I don’t think a code block in the middle of a org file should impact iCalendar export.
The code block begins with #BEGIN_SRC emacs-lisp and is highlighted correctly. I’m not sure why it says “no language for src block”.
Regards,

JI, Xiang