Has anyone ever seen this error?

make[4]: Leaving directory `/home/tscharner/motif/demos/lib/Exm/wml'
make[4]: Entering directory `/home/tscharner/motif/demos/lib/Exm'
make[4]: Nothing to be done for `all-am'.
make[4]: Leaving directory `/home/tscharner/motif/demos/lib/Exm'
make[3]: Leaving directory `/home/tscharner/motif/demos/lib/Exm'
make[3]: Entering directory `/home/tscharner/motif/demos/lib'
make[3]: Nothing to be done for `all-am'.
make[3]: Leaving directory `/home/tscharner/motif/demos/lib'
make[2]: Leaving directory `/home/tscharner/motif/demos/lib'
Making all in programs
make[2]: Entering directory `/home/tscharner/motif/demos/programs'
Making all in airport
make[3]: Entering directory `/home/tscharner/motif/demos/programs/airport'
make[3]: Nothing to be done for `all'.
make[3]: Leaving directory `/home/tscharner/motif/demos/programs/airport'
Making all in animate
make[3]: Entering directory `/home/tscharner/motif/demos/programs/animate'
../../../clients/uil/uil -o dog.uid dog.uil -I./../../../clients/uil -I../../../clients/uil

Error: $LANG contains an unknown character set

Info: no UID file was produced

Info: errors: 1 warnings: 0 informationals: 1
make[3]: *** [dog.uid] Error 1
make[3]: Leaving directory `/home/tscharner/motif/demos/programs/animate'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/home/tscharner/motif/demos/programs'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/home/tscharner/motif/demos'
make: *** [all-recursive] Error 1

I am trying to install motif to use plugins with opera. Any help?