We made every effort to make the upgrade from bootstrap_form v4 (Bootstrap 4) to bootstrap_form 5.0 (Bootstrap 5) as easy as possible. However, Bootstrap 5 is fundamentally different from Bootstrap 4, so some changes may be necessary in your code.
Upgrading bootstrap_form to version 5 means you must upgrade your whole application to Bootstrap 5. Read the Bootstrap 5 migration guide to see what changes you have to make to your views. This will also help you understand changes you might have to make to your bootstrap_form code.
As explained in #560, the role="form" attribute generated by bootstrap_4 caused the W3C validator to output a warning. The role="form" attribute was deprecated in the 4.5.0 and is being remove completely in 5.0.0. This has no impact on bootstrap_form code itself, but may affect your application if it depended on a form having this attribute set. (Issue #569)
The errors_on helper now wraps the error message in a CSS class invalid-feedback, instead of alert and alert-danger, as before.
This will display the error as any other Bootstrap inline form error, instead of displaying it as an Bootstrap alert.
You can use the custom_class options for this helper with alert alert-danger to restore the old behaviour:
<%= f.errors_on :tasks, custom_class: 'alert alert-danger' %>