I have had the same problem.
I have located that for me the problem was in DrWeb. When looking in the kmm source, I see that I use $LINKURL in the menugrayed condition line.
As this line is parsed to build the menu dynamically, it fails.
I think that all the macro using this checking mode can be bugged. I'll clean all the kmm files for next version.
To easily locate the kmm(s) files which are bugged :
F2 > Plugins K-Meleon > Extension macro
uncheck a part of the macro which are is 'user defined'
test
by unchecking and checking it, you can find all the concerned kmm files.
Another way quicker: with a tool (Pspad can do it) search for the string $LINKURL in files to locate it and then correct it.
As you can see, more than one kmm file can be concerned.
A+
Mozilla/5.0 (x11; U; Linux x86_64; fr-FR; rv:38.0) Gecko/20100101 Ubuntu/12.04 K-Meleon/76.0
Web:
http://jujuland.pagesperso-orange.fr/
Mail : alain [dot] aupeix [at] wanadoo [dot] fr
Ubuntu 12.04 - Gramps 3.4.9 - Harbour 3.2.0 - Hwgui 2.20-3 - K-Meleon 76.0 rc