Unable to boot after unexpected shutdown

Hello,

First post here and a beginner with Linux and Ubuntu Mate.

Help! My laptop unexpectedly shutdown and when trying to restart I get the GNU GRUB version 2.04 page.
I need to use a grub> command to get my laptop running.

What do I need to do?

Please help!

Thank you in advance

Update

Within gnu grub

Grub> exit

I reached my usual log- in window

I followed advice to open my Mate terminal
Tried ‘Sudo update-grub’

When booting I always reach the gnu grub
‘Minimal bash-like line editing thingy.

What do I need to do to ensure Linux Mate will boot without hesitations.

I use only Linux Mate on this laptop.

Any ideas anyone?

Thanks again