Hi Peter, the message you get is a side effect of the buffer code for mkii, although i have a fix for the context code it won't be applied because unwanted side effects can't be be guaranteed. As you should have noticed your example worked in a older release where i used a different method to store the letter content which was changed due to some limitations (e.g. \startlines is not possible). You can force the old processing method with \setupletterstyle [method=store]. Other solutions are to add \relay after \startletter because this stops contexts optional argument grabber or to leave a blank line after \startletter. Wolfgang