Vesta Control Panel - Forum

I have the lateste install of Debian 7 and VestaCP working great. But now I want to upgrade to Debian 8. I tried on a test server to just run a dist-upgrade, and maybe I overwrote some conf-files I shouldn't, but it ended in an error:
......
Processing triggers for initramfs-tools (0.120+deb8u1) ...
update-initramfs: Generating /boot/initrd.img-3.16.0-4-amd64
Errors were encountered while processing:
apache2
libapache2-mod-php5
apache2.2-common
apache2-mpm-prefork
E: Sub-process /usr/bin/dpkg returned an error code (1)

So I wonder if you could recommend a better approach for upgrading from Debian 7 to Debian 8?

Regards
Øystein

Maybe this is a easier question. Is it not recommended to upgrade from Debian 7 to Debian 8?

And the final question. What do you charge for an Debian 7 to Debian 8.2 upgrade. Remember, I bought the File Manager :-)