When I have texis installed in a directory other than /usr/local/morph3 I am getting eroneous WARNING messages about being unable to execute monitor from that directory during calls to n_texis().
Make sure you've installed Texis using the install script, not by copying files. The libs that were used to link in n_texis() for your executable probably weren't patched to contain the install directory. Either make /usr/local/morph3 a symlink to the install directory, or run:
gwpatch -p/your/install/dir your-executable
on the executable in question. (You could also try running it on api/libtexis.a and re-linking.)