Upgrading Drupal

hi I have the next error after upgrade Drupal 9

Mismatched entity and/or field definitions

The following changes were detected in the entity type and field definitions.

I'm trying to do this upgrade in Composer:

composer update drupal/core-recommended --with-all-dependencies

I get the following error message that I don't understand:

Your requirements could not be resolved to an installable set of packages.

I just upgrade from core 8.9 to 9.2 and webforms module 8.x-5.27  to 6.0.4 on my local test server. My web forms no longer display on any pages but the forms are still in the admin side.  

I already tried clearning the cache and using drush webform-repair.   Any ideas?

In my logs I get this message: 

I need to upgrade my drupal isntance to 9.2  I've installed Upgrade Status 8.x-3.7.  When I run the upgrade status, I get a warning: 

Hello!

After my update failed I restored the host files and the db. The outward-facing site still shows " We'll be back soon. We are currently updating our shop and will be back really soon. Thanks for your patience.". When I log in as admin I get no errors but I go to the same display. 

How do I get the site out of maintenance mode?