Please update FVWM to 2.6.7 version https://github.com/fvwmorg/fvwm/releases It works fine for me (FreeBSD 11.0-RELEASE-p2 amd64), it seems that "patch-configure" is no longer needed.
There are issues with fvwm 2.6.7 on -CURRENT. ./configure needs to be taught to use iconv form ports instead.
(In reply to ILUXA from comment #0) Reinstall using the upcoming fvwm2 update. There are numerous corrections, not the least of which: pkg-plist and a couple of patches for clang 3.9.0/3.9.1.
A commit references this bug: Author: cy Date: Tue Dec 20 07:15:29 UTC 2016 New revision: 428978 URL: https://svnweb.freebsd.org/changeset/ports/428978 Log: Update 2.6.6 --> 2.6.7 PR: 215337 Changes: head/x11-wm/fvwm2/Makefile head/x11-wm/fvwm2/distinfo head/x11-wm/fvwm2/files/patch-configure head/x11-wm/fvwm2/files/patch-default-config__Makefile.in head/x11-wm/fvwm2/files/patch-libs-Ficonv.c head/x11-wm/fvwm2/files/system.fvwm2rc head/x11-wm/fvwm2/pkg-plist
(In reply to Cy Schubert from comment #2) Many Thanks! It works like a charm!
Found a problem with fvwm-menu-desktop in fvwm 2.6.7. https://i.imgur.com/pn7PrCk.png To make it work, all "/etc/xdg/menus" in "/usr/local/bin/fvwm-menu-desktop" should be replaced with "/usr/local/etc/xdg/menus".
A commit references this bug: Author: cy Date: Wed Dec 21 00:42:06 UTC 2016 New revision: 429037 URL: https://svnweb.freebsd.org/changeset/ports/429037 Log: Make ${LOCALBASE}/etc/xdg/menus the home of XDG menus. PR: 215337 Changes: head/x11-wm/fvwm2/Makefile