Common-Issues.md

@@ -3,6 +3,18 @@ Usually trying the following resolves all issues:
 * Invalidate cache and restart (JetBrains IDEs).
 * Make sure `application.yaml` contains the latest changes made to `application.template.yaml`.
 
+## Disappearing Form Elements
+##### Where?
+When using Thymeleaf with nested `<form>` elements.
+##### Solution:
+Try to avoid nesting forms, but if necessary, create each `<form>` element unnested, then use the `form=ID` on each `<input>` element. This will allow you to create nested forms without problems. Examples can be found in TAM source code.
+
+## Missing `_csrf` Field in Forms
+##### Where?
+Usually in Queue, once the service has started, but you are having issues submitting forms.
+##### Solution:
+To ensure forms have a `_csrf` field, either make sure the form uses `th:action`, as this automagically adds the field or add it by hand as a hidden input field.
+
 ## Mail Server Error
 ##### Where?
 Usually in Queue, during the first start-up.