Updating to 5.0.8 gives an error:

The upgrader uses PHP sessions to store data, however PHP sessions are currently not working correctly on your server. This is an issue you will need to contact your host about.

How do I reset the update to update again?

You'd want to ensure that PHP sessions are working on your server. If you are unsure how to do this, please contact your hosting provider.

I contacted the hosting, it reset the php sessions. I have updated the cms, the website is working. But when logging into the admin panel, it gives an error and nothing more can be done there.

1 hour ago, zavsegda said:

I contacted the hosting, it reset the php sessions. I have updated the cms, the website is working. But when logging into the admin panel, it gives an error and nothing more can be done there.

Can you check your server error log and see if there are any error messages logged in there most recently?

10 minutes ago, Miss_B said:

Не могли бы вы проверить журнал ошибок вашего сервера и посмотреть, не было ли там недавно сообщений об ошибках?

I contacted the hosting, and they started fixing the database. Everything worked

1 hour ago, zavsegda said:

I contacted the hosting, and they started fixing the database. Everything worked

Glad to see that everything has been fixed.