virtualbox.org

Hello.
I have used virtualbox since august. I installed Ubuntu 14.04 on virtual machine. Virtual machine and Ubuntu works OK although virtual machine showed me this message when Ubuntu was initialized:
"VBoxClient: The virtualbox kernel service is not running. Exiting"
I kept on using it without pay attention at this warning because all functions worked correctly. But this morning when I tried to open Ubuntu on Virtual Box, I can´t do it.
First of all, Ubuntu asked me for my password when it have been configured for autostart. When I wrote my password screen turned black and appeared this warning like other times but this time, Ubuntu didn´t continue with initiation and went back to the point that it asked for my password. Obviosly, I can´t use the terminal because I can´t acces to Ubuntu.
Does someone know how I can fix this problem?
Thank you so much

Sounds like you have tried to install the guest additions and it failed.
You have two choices.

• 1) when the password screen shows enter a tty windows and repair from there.
  2) use recovery mode at boot.

Then fix the additions install or install them again. I would caution you to watch closely this time because the original error that tells you what went wrong is very important.

And if it wouldn't be nuisance, could you say me how I can do that?
Because I have heard about recovery mode, but I have never used it and I don't know what is tty.
Thank you so much

Sure I can tell you what to do but if you don't know what a tty window is or how to use a recovery boot, you might be better off re-installing the OS.

• To enter a tty window use the host key ( emulates ctrl+alt ) and F2 key at the same time. This will give you a terminal window is which you can run your repairs.
  To enter a recovery window with Ubuntu you hold the shift key down as you boot the guest and then follow the instructions.

At last, it works!!
I used that you said, ctrl+alt+shift+f2 when virtual machine was startingo to run, then 4 options appeared and I selected "advanced options" > recovery mode > fix broken packages (I have translate that from spanish so I am not sure that it appears exactly to you). Then, it run the console and began to apear some lines of code. When it finished, Ubuntu began to run and I could use all his functions, but the message about the kernel appeared again. Then I reinstalled the guest additions because I read that after Kernel's update I could be fail. After that, the message about kernel dessapeared and I can use the Ubuntu on my virtual machine perfectly.
Thank you so much by your aid and sorry for my english

Had this very error and tried numerous approaches to resolve including upgrading and downgrading the kernel installing devel kernels etc. etc. but the below worked for me straight away -
sudo vi /etc/X11/Xsession.d/98vboxadd-xclient
Then you need to find the line with notify-send "VBoxClient: the VirtualBox kernel service is not running. Exiting."
For me I changed notify-send to echo so it looks like this
echo "VBoxClient: the VirtualBox kernel service is not running. Exiting."

Restarted and no error message - Thank God! this was so annoying