Sleeping Kobo is not waking up
We all have a bad night so now and again and keep snoozing. But what about a Kobo e-reader that does not wake up?

The book you stopped reading yesterday is still on the display, but when you press the on button, only the backlight of the reader goes on. What to do now to make the Kobo wake up?
Put the Kobo on the charger
Just now, I wanted or continue reading and had that exact issue. The Kobo was sleeping and when I wanted to wake it up only the backlight started giving light, but no book appeared.
Pressing the on button did not help. The solution for a sleeping Kobo not waking up is:
Connect the e-reader to the charger and then press the on button for 15 seconds.
The Kobo e-reader woke up immediately, but it had to reboot the software. After that, the Kobo reader worked. Of course, I needed to keep the Kobo charging for a while.
Possible causes of crashes
Two things to keep in mind is the battery and the system software.
Battery
I have noticed that when the Kobo Clara e-reader is frozen, there is often something wrong with the battery. Poorly charged, for instance with a backup battery. Also, a different charge load is indicated than the one indicated later, after startup.
Try to keep the Kobo charged.
System software
Another possible cause is outdated system software. It is good to keep this up to date.
Keep system software up to date