I am trying to process a document I wrote in 2009 using mkii. I am
modifying it to work with mkiv.

When I run

context mydoc.tex

the process starts and after some time it stops and shows an asterisk (*)
waiting for a command. I then type in "\end", and it resumes. Finally it
ouputs "mydoc.pdf". There are still some things to fix (ie section numbers)
but in general the document is ok.

I can't see any "error" message although I got a lot of "Overfull \hbox..."
and "Underfull \hbox..." messages.

What can be the reason?