Upgrading Drupal

I am very excited with a question of the upgrade from 8.0.5 (now) to 8.1...
Update process from the 8.0.х to 8.1 will be the same as with the 8.0.0 to 8.0.1... 8.0.5?
Or to be more complex and require data migration and rework of 8.0.x theme?
The modules, which work under 8.0 will work in 8.1?

Thank U.

I am doing drupal to drupal upgrade but for some reason I am getting this warning on Step 6: Review:

Warning: Invalid argument supplied for foreach() in MigrateD2DWizard->reviewForm() (line 932 of /usr/local/www/htdocs/D743/sites/all/modules/migrate_d2d/migrate_d2d_ui/migrate_d2d_ui.migrate.inc).

After clicking "Save import settings and run import" on STEP 6 I get it goes to a blank page.

Any thoughts?

I've run and re-run migrate-upgrade on a Drupal 6 site, with an impressive amount of success, but with some major (and puzzling) problems.

Specifically, none of the "Date" fields from the D6 CCK nodes are migrating. /upgrade page confirms that date & date.api are "missing upgrade paths".

Has anyone managed to migrate a simple Date field from 6 to 8?

EDIT:

It turns out an issue has been opened on this exact question - https://www.drupal.org/node/2566779

Hello, I have one site on drupla 7.32. And I have upgraded it in a test environment and encountered with starnge behavior. After upgrading from 7.32 to 7.43 Status report page still show me that there is a security update available for my version of Drupal.

I attempted an upgrade of Drupal 6 to Drupal 7. Now I am getting the message "Fatal error: Unsupported operand types in update7/includes/theme.inc on line 1088".

I have looked at the theme.inc at line 1088 and I don't know what it is complaining about.

This is the area of code to which it is referring:

sql errors were stopping my upgrade processes, but the main problem were sql tables that existed.
I had about 50 sql tables I needed to drop, I think they came from a failed upgrade attempt. I found this post that really helped.
https://support.mayfirst.org/ticket/8112
Here is a list of the sql table to drop, about 50 of them.
https://support.mayfirst.org/attachment/ticket/8112/upgrade-notes.org