Thank you. I check it, and you are right. I forgot to include the definitions when I cut and paste that part of the code. I thought the problem was related to the btex command, but it's not. The first line is: u=1.000mm; linecap:=butt; linejoin:=mitered; path pp; picture pic; labeloffset:=0; I compared it with your code. The "numeric u;" definition is missing in my file. I have included it and now it works!! It's really weird since I compiled it in 2009 and it worked as is. I still have the pdf output file...?? Finally I have a problem in this line: externalfigure "aciddrops1.png" xscaled 80.13u yscaled 60.09u shifted (69.85u,20.30u) ; Then I got: terminal: >> picture ! Isolated expression. <to be read again> ; <*> ...3u yscaled 60.09u shifted (69.85u,20.30u) ; ; . system > tex > error on line 99 in file kk2.tex: terminal: >> picture ! Isolated expression. <to be read again> ; <*> ...3u yscaled 60.09u shifted (69.85u,20.30u) ; ; ... 89 fill pp--cycle withcolor (0.000,0.000,0.000); 90 pp:=(150.24u,73.96u)--(152.93u,72.91u)--(153.10u,74.30u)--(150.24u,73.96u); 91 draw pp--cycle withpen pencircle scaled 0.30mm withcolor (0.000,0.000,0.000); 92 93 setbounds currentpicture to (67.85u,18.30u)--(197.56u,18.30u)--(197.56u,102.23u)--(67.85u,102.23u)--cycle; 94 95 externalfigure "aciddrops1.png" xscaled 80.13u yscaled 60.09u shifted (69.85u,20.30u) ; 96 97 \stopuseMPgraphic 98 99 >> \useMPgraphic{gh} 100 101 \stoptext 102 <inserted text> ...re.mp ; fi ; ;;;;]===], false)} \processMPgraphic ...e ;\!!es , \MPaskedfigure )}} \egroup \placeMPgraphic \d... \handleuseMPgraphic ...hics \processMPgraphic {#3} \endgroup \douseMPgraphic ...{\@@MPG \currentMPgraphicname } \empty \endMPgraphicgroup <to be read again> l.99 \useMPgraphic{gh}