How To Fix Error loading component: com fields Component not found in Joomla

1. Warning Error loading component: com_fields, Component not found
Description

When updating Joomla 3.6.5 site to 3.7, many users have seen the warning error:

“Warning: Error loading component: com_fields, Component not found”

How to fix

Step 1: Go to Extensions/Manage/Discover
Step 2: Click on “Discover” button, enter “fields” in search edit and select all extensions it shows
Step 3: Click on “Install” button and reload the page

2. No access to menu manager after updating to J3.7
Description

Immediately after updating from Joomla 3.6.5 to 3.7, you have no way to access the backend menu manager. The following message appears when you try to go to Menu → Manage:

And if you click on your Main menu, the below error will appear:

How to fix

Step 1: Go to Extensions → Manage → Database. In this step, you will see a warning “Database is not up to date” and a list of database problems as below:

Step 2: Click the Fix button on the upper left. If the database issues are resolved, you will see the notice “Database table structure is up to date”.