[j-nsp] Installation of jweb on MX80 fails

[Alex D.]

Hello,
i have a Juniper MX80 running JUNOS 10.4R6.5. I installed the domestic 
version jinstall-ppc-10.4R6.5-domestic-signed.tgz with ssh daemon. Now i 
tried to install package jweb-10.4R6.5-signed.tgz, but while validation 
i got the following error:

Web management gatekeeper process: mgd: unable to execute 
/usr/sbin/httpd-gk: Bad file descriptor
mgd: error: configuration check-out failed

Is someone here who knows this problem and can give me a hint how to fix it?

Thanks in advance...
Regards,
alex