Hello,
I noticed that after installing sogo, and wbtop, then installing MySQL, and wb server, it becomes not possible to install freepabx on nethserver,
I am not sure why.
I tired previously installing freepabx and it worked, but I did not have webtop installed then.
Is there any related error on /var/log/messages ?
It seems to have nothing to do with webtop, it’s like epel lost another package named iksemel, I had following entry in my /var/log/messages:
Jul 16 01:29:00 testserver pkgaction[40041]: [YumRPMCheckError] [u'ERROR with transaction check vs depsolve:', 'libiksemel.so.3()(64bit) is needed by asterisk13-core-13.17.2-3.ns7.x86_64']
After installing it from some other repo, freepbx installs without problems:
yum install http://springdale.math.ias.edu/data/puias/unsupported/7/x86_64//iksemel-1.4-6.sdl7.x86_64.rpm
https://centos.pkgs.org/7/puias-unsupported-x86_64/iksemel-1.4-6.sdl7.x86_64.rpm.html
thanks it works fine after yum installing iksemel
you’re right, epel removed iksemel.
Since Asterisk features that rely on iksemel should be useless on NS, I rebuilt Asterisk without it. The package is in testing https://github.com/NethServer/dev/issues/5524
It works as expected. Iksemel not needed anymore. Module updates in web UI are working without error. 
Fix released