Plesk domain create fails

Plesk domain create fails

i need the help of the community - i'm running our startup on a LAMP
server here at a little hoster in switzerland.. after months of
developing, i made an update to the system this weekend and now, i'm
realizing that my plesk installation on the server has a serious problem.
you have to know - for our business, it is essential to have an automated
process who creates/modifies or deletes subdomains and domain-aliases -
everything solved through the plesk-cli tools, pretty well so far.
this system was working for at least 1.5 years now, without any further
manipulation to it - it was just running. after i made the update this
weekend, i'm facing the problem that we just can't create any
subdomain/domain-alias anymore. after some investigation, it's getting
even worse - the error thrown comes directly from plesk and i'm just
sitting in front of my computer like.. "WOW"..
you know, i never made something with plesk! how can this stupid software
just stops working without any manipulation from my side? and just to be
clear - it is a root server... MY root server, no ones else.. i'm the only
one who should do anything to it but for me it is obvious now, that the
hoster has made some "mistakes" in the meanwhile - but they say (not a big
surprise) that "they did nothing".... sure sceptical-dog
now, the help i wanted to ask for.. does anybody know this exact failure
of plesk and maybe, knows how it happen or how it can be fixed?
Error: hosting update is failed: sh:
/opt/psa/admin/bin/vhostmng-structure: No such file or directory
The full log can be viewed here: http://pastebin.com/PDTLPZep