I have a freshly upgraded 17.04 laptop (HP Probook 450G3), with only one OS instlled. I wanted to enable hibernation, so followed instructions from here: https://help.ubuntu.com/stable/ubuntu-help/power-hibernate.html
After the first command 'systemctl hibernate', when I tried to restart the system, it say: BOOTMGR is missing. Press CTRL+ALD+DEL to reatart.
I am traveling right now and have internet access only on my mobile phone. I can download the ISO and also have a USB pen drive. But don't have any bootable iso.
Any suggestions?
If you are able to, put Ubuntu onto your pen drive, as you probably did when installing Ubuntu; then boot from said USB on your laptop, and install and run a program called "Boot Repair" using these commands;
Then click "Recommended Repair" and do as it tells you.