What does this error mean? (publishable_transitions_for)

[Catbus Omnibus]

I encountered an error when submitting a form.
The form is submitted with a required field and the field left blank.
display :string, :required
What does the errors mean? and how to fix it?
undefined method `publishable_transitions_for' for nil:NilClass
1: <show-page>
2:   <append-content-header:>
3:     <transition-buttons/>
4:   </append-content-header:>
5:   <collection: replace>
6:   <table-plus:a_objects fields="this, display">
7:     <empty-message:>No objects match your criteria</empty-message:>
Error stack
app/views/a_apps/show.dryml:4:in `block (4 levels) in render_page'
app/views/a_apps/show.dryml:2:in `block (3 levels) in render_page'
app/views/taglibs/auto/rapid/pages.dryml:546:in `block (8 levels) in show_page__for_a_object'
app/views/taglibs/auto/rapid/pages.dryml:545:in `block (7 levels) in show_page__for_a_object'
app/views/taglibs/auto/rapid/pages.dryml:545:in `block (6 levels) in show_page__for_a_object'
app/views/taglibs/auto/rapid/pages.dryml:544:in `block (5 levels) in show_page__for_a_object'
app/views/taglibs/auto/rapid/pages.dryml:544:in `block (4 levels) in show_page__for_a_object'
app/views/taglibs/auto/rapid/pages.dryml:543:in `block (3 levels) in show_page__for_a_object'
app/views/taglibs/auto/rapid/pages.dryml:539:in `block in show_page__for_a_object'
app/views/taglibs/auto/rapid/pages.dryml:538:in `show_page__for_a_object'
app/views/a_apps/show.dryml:1:in `block in render_page'
app/views/a_apps/show.dryml:1:in `render_page'
app/views/a_apps/show.dryml:1:in `_app_views_a_apps_show_dryml___4460466109160282585_70153904473400'

[Bryan Larsen]

In the future, when you post a backtrace, please post the full
backtrace. You can get that either from the web page error by
clicking on the full backtrace tab, or by modifying
config/initiailizers/backtrace_silencers.rb.

But in this case, I can take a pretty good guess at what's failing.
It's this line in transition_button.dryml:

transitions = this.lifecycle.publishable_transitions_for(current_user)

It's saying that this.lifecycle is nil, which means that this is not a
hobo model, a this is a hobo model that doesn't have a lifecycle
defined on it.

If you need more help, please post the code for your corresponding
controller action.

Bryan

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