okay this was quite an odyssey
had to reinstall tapatalk addon (no clue why, i copied databases and sources from original server...)
so i have manually undone the patches tapatalk installation made to the sources (i.e. edit all source files and search for tapatalk's modifications)
and then reinstall the plugin:
but this required to allow FTP access for chmod and file operations.
but the vsftp didnt allow SITE CHMOD for the current chrooted user (although it was enabled and rights were correct plus it worked from cmdline)
and with the in.ftpd chroot needed all binaries in chrooted environment too.
non-chrooted didnt work due to SMF not wanting to accept the "root path" to prefix to file operations.
but finally it works