Module can't update after updating core I updated my Drupal 8 website from 8.2 to 8.3. I have a module that has a block and includes a configuration form which has various data form fields. 
The block of the module appears to work fine. 
But when I try to update any of the configuration data it simply doesn't change anything! Something to do with not updating the database, maybe?

Example: I want to change the modules block name. 
The old name is "oldname" and I want it to be "newname". After typing in the new name on the configuration page and clicking save the name will still remain "oldname".

There is not a single error within Drupal or my servers log file that would explain this. 
Is there anywhere else I can look to find what the problem is? 

What's changed with the new version of Drupal that might cause this?

After searching for awhile and cleaning out some old modules from the database I've finally come across an error relating to forms. It' quite long but here's the first part:
Warning: strip_tags() expects parameter 1 to be string, array given in Drupal\favorites\Form\AddForm->buildForm()
Use drush config-edit, as stated in the docs.

Or implement an upgrade path for you module, see hook_update_N.