I had analogical problem because my pc lost power and something in maria db crashed. I have a lot work on local so i wanted to try to fix it instead restore/create fresh db. I did it so i would to share with my solution:
Go to mariadb bin folder for example:
Find my.ini and open.
Simply add single line:
after [mysqld] group.
Now we are able to enter to mysql and phpmyadmin, in my case i use phpmyadmin and i get many errors on home page about crashed user table so i run SQL queries:
CHECK TABLE user;
REPAIR TABLE user;
And voilà. Now we can remove skip-grant-tables just in case.