validates_timeliness | time validation plugin for ActiveModel and Rails | Date Time Utils library

I'm trying to get my head around the order/precedence with which Rails processes validation checks. Let me give an example.

In my model class I have these validation checks and custom validation methods:

I am trying to migrate from Rails 4.2 to Rails 5.0 (running on ruby 2.3) (see plan here https://stackoverflow.com/a/38443616/7374136)

The plan is to:

1. Update the rails gem and all dependencies.
2. Run tests (covering almost our whole code base) for depreciations and fix them.
3. Run rake rails:update to update Rails
4. Adapt the configuration, application classes, breaking changes, ...

Nevertheless, I am blocked at the first step already, updating the rails gem and dependencies. gem 'rails', '4.2.5' -> gem 'rails', '~> 5.0' running: bundle update rails.

I faced multiple dependencies issues, which I fixed by looking for any dependencies that ultimately require rails to be less than 5, and see if those can be updated. Running:

The default behavior of Devise should be to send the user to the root path after login. Mine is failing to do that and instead is simply rendering the login page again. It is logging the user in. It is just not redirecting properly.

For some reason any time I use a sass glob pattern (e.g. @import "recommends/**/*"; ) and then go to compile my assets for production (it works in development) it's not working (is throwing a File to import not found or unreadable error`).

Any thoughts as to that for which I had not accounted?

Gemfile:

I want to update my dependencies, it works if I specify the kaminari version to be 0.17.0

But now with this version of kaminari i can't make rails_admin work anymore, see here the error I got => https://github.com/sferik/rails_admin/issues/2939

When I don't specify a version of kaminari i get this error =>