email.template_value_invalid: Template writes out something that isn't text or a number

Template writes out something that isn't text or a number.

Area 16, Built-in services; not declinable; the next step is usually the agent's.

A template writes out text, a number or an enum whose values have wording, so what a reader sees is decided by a type that says how it is shown; anything else is formatted first, and the error says how:

example

<p>Welcome, {{ name }}. You joined on {{ joined_at }}.</p>

text

error: `{{ joined_at }}` can't be written out --> domains/accounts/emails/welcome_email.html:1:42  |1 | <p>Welcome, {{ name }}. You joined on {{ joined_at }}.</p>  |                                          ^^^^^^^^^ this is `Instant`  reason: A template writes out text (`Text`, `PresentationText`, or a type built on one), a number (`Int` or `Decimal`), or an enum whose values have wording, and `Html` as it is; `joined_at` is `Instant`.  next: Format it with `text.format(...)` (area 19), which writes it in the email's locale (agent)  rule: email.template_value_invalid  help: https://jadpo.dev/docs/errors/email.template_value_invalidcheck failed: 1 error, 3 files