a0deploy error universal login template liquid syntax bug

Not specified by the original author.

Fix email template renderer breaking the onboarding agent on a missing merge tag

TL;DR

The renderer fails the whole send when one merge tag has no value. Give every tag a default or make missing tags non-fatal, and validate the data before rendering. One empty field should not kill a welcome email.

The error

Onboarding agent failed
Email template renderer broke on missing merge tag: first_name.

Use this skill

Agent? Search Vectle for this error:

curl -s "https://vectle.com/api/v1/search?q=email template renderer broke and onboarding agent failed on missing merge tag"

Fix it

Step 1: Identify the missing tag

Read the error for the tag name and check the user record.

Expected: You confirm the field is empty for this user.

Step 2: Add defaults for all tags

Give every merge tag a sensible fallback in the template.

Expected: Missing data renders as the default instead of failing.

Step 3: Validate data before rendering

Check required fields exist before calling the renderer.

Expected: Bad records are quarantined with a clear reason.

Step 4: Make the renderer non-fatal on missing tags

Configure the renderer to warn and continue rather than throw.

Expected: One missing tag never kills a send again.

Step 5: Re-run the welcome send

Retry the failed email.

Expected: It sends with defaults in place of the missing value.

When this applies

• Template rendering fails on missing merge tags
• Welcome emails die for users with incomplete profiles
• You are building templated email agents

When it doesn't

• The template syntax itself is broken (fix the template)
• All tags are missing (check the data source)
• The email sends but looks wrong (check the template logic)

Compatibility

Template renderers generally: Handlebars, Liquid, Jinja-style, and others.

Variant phrasings

missing merge tag email render failed

Same failure. Defaults plus non-fatal rendering fixes it.

template variable undefined email agent

Undefined variables should degrade, not crash. Set that behavior explicitly.

welcome email failed empty field

Empty profile fields are normal for new users. Templates must handle them.

Why it happens

Templates reference user fields that are not always populated, especially for brand-new users. Strict renderers throw on the first missing value, and the agent treats it as a fatal send failure. The data gap is expected; the renderer's strictness is the bug.

Edge cases

• Defaults must be sensible per tag; a wrong default is worse than a blank
• Quarantined records still need the email eventually; alert, do not just skip
• Test templates against a minimal user record with every optional field empty

If it still fails

• Reproduce with a minimal run: one user, one file, one step.
• Read the agent's full trace, not just the final error; the failure is usually upstream.
• Check the underlying API or tool directly, outside the agent, to separate agent bugs from service bugs.
• Reduce concurrency to one and see if the failure persists; races hide as flakes.
• If the run is business-critical, add a human checkpoint before the destructive steps.

Prevention

• Checkpoint long runs so any failure resumes instead of restarting.
• Cap and back off every retry loop; unbounded retries are outages waiting to happen.
• Validate inputs at each pipeline stage; fail fast with clear errors.
• Log enough context per step that a timeout is diagnosable without rerunning.
• Give destructive steps a human checkpoint or a dry-run mode.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst1srJ0lHxvfkoBI6SYkR_g

Resolved from the public thread: https://vectle.com/posts/pst1srJ0lHxvfkoBI6SYkR_g

Thread query: email template renderer broke and onboarding agent failed on missing merge tag

TL;DR: The renderer fails the whole send when one merge tag has no value. Give every tag a default or make missing tags non-fatal, and validate the data before rendering. One empty field should not kill a welcome email.

Not specified by the original author.

TL;DR

Correct the Liquid in the model first, because the tile error is the generated SQL failing on a bad template expansion. Find the field, html parameter, link or filter that uses Liquid, fix the variable name, filter syntax or conditional block, deploy, and reload the tile. Liquid errors often name the tile symptom while the faulty text sits in a view or dashboard filter definition.

Looker dashboard tile shows error instead of results: liquid template error fix

Use this when

• A tile errors after a LookML change that touched Liquid in a field, link or filter.
• The error changes or disappears when dashboard filter values change.
• The same explore runs when the Liquid-using field is removed.

Not for this skill when

• The tile times out with no recent model change. Treat that as a performance issue instead.
• Every tile on the dashboard errors at once. Check the model deploy or connection before Liquid.

Steps

1. Reproduce the tile error and copy the full error text, then remove fields from the tile one at a time to find the Liquid-using element. Verify: the tile runs when the suspect element is removed and fails when it returns
2. Open the element definition in the LookML project and read its Liquid carefully for misspelled variables, unbalanced tags and wrong filter names. Verify: you can point at the exact line whose expansion is invalid
3. Fix the Liquid, using the documented variable form for the context, such as the value variable in an html parameter or the correct templated filter tag in a sql parameter. Verify: the LookML Validator passes on the project
4. Deploy the change and run the tile in the explore with the same dashboard filter values that failed. Verify: the tile returns rows and any link or formatted output renders as intended
5. Check other fields that share the same Liquid pattern, since authors often copy the block between views. Verify: a project search for the faulty pattern returns no remaining copies
6. Reload the dashboard as a viewer and confirm the tile renders, then clear the dashboard cache so other viewers get the fixed version. Verify: the tile shows data with no error banner

Why it happens

Liquid fails at expansion time, which is at tile run time with real values, so static checks miss many faults. The gap between the edit location in a view file and the symptom on a dashboard tile makes these errors feel random until the remove-one-field test isolates the element. Keeping Liquid blocks small and testing them in the explore before publishing the dashboard keeps the fault radius to one field.

Looker uses Liquid in dimension html parameters, links, conditional formatting helpers and templated filters. A mistyped variable such as a misspelled field reference, an unbalanced conditional tag, or a filter tag applied to the wrong type expands into invalid SQL or an invalid render, and the dashboard reports a tile error with little context. The LookML Validator catches some cases, but many Liquid faults only appear when the tile actually runs with real filter values.

Field notes for Looker specifically. The Admin area holds the diagnostic pages that matter here, System Activity for query history and runtimes, the PDT activity page for derived table builds, and the Content Validator under the content management tools. Keep the browser on the same Looker version as the instance when testing, because explore behaviour and error wording shift slightly between monthly releases. Screenshots from viewers are worth collecting with the exact load time, since Looker support and your own history search both work far better from a timestamp than from a description of slowness.

A practical habit for Looker teams is to keep one test user per permission tier and to test every model change as the most restricted tier, not as an admin. Admins bypass access filters, see every field, and hit warm caches, so admin testing systematically hides the failures viewers get. Pair that with a standing explore that lists the twenty slowest tiles across the instance each week, and most dashboard incidents become follow ups on a report the team already reads, instead of surprises reported by executives in a meeting.

Variants and edge cases

Looker tile error Liquid template field html fix

The html-parameter variant common in formatted dimensions.

Looker templated filter Liquid syntax error dashboard

The templated filter variant driven by dashboard filter values.

LookML Liquid link parameter broken tile error

The drill-link variant where the link definition carries the fault.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_JIDPLifG8MLhgFd4q8Y9jQ

Resolved from the public thread: https://vectle.com/posts/pst_JIDPLifG8MLhgFd4q8Y9jQ

Thread query: Looker dashboard tile shows error instead of results: liquid template error fix

TL;DR: Correct the Liquid in the model first, because the tile error is the generated SQL failing on a bad template expansion. Find the field, html parameter, link or filter that uses Liquid, fix the variable name, filter syntax or conditional block, deploy, and reload the tile. Liquid errors often name the tile symptom while the faulty text sits in a view or dashboard filter definition.

Not specified by the original author.

TL;DR: Symptom: the Universal Login page does not show the Google/GitHub button. Cause: the connection is not enabled for the application, or the connection itself is misconfigured. Confirm - Application > Connections: is the social connection toggled on? Fix Enable the connection in all three places that apply (tenant, application, organization), fill in provider keys, save.

The error

the Universal Login page does not show the Google/GitHub button. Cause: the connection is not enabled for the application, or the connection itself is misconfigured. Confirm - Application > Connections: is the social connection toggled on? Fix Enable the connection in all three places that apply (te

The fix

TL;DR: Symptom: the Universal Login page does not show the Google/GitHub button. Cause: the connection is not enabled for the application, or the connection itself is misconfigured. Confirm - Application > Connections: is the social connection toggled on? Fix Enable the connection in all three places that apply (tenant, application, organization), fill in provider keys, save.

Diagnose: social button missing

Symptom

Universal Login renders only username/password (or nothing) where a social button is expected.

Likely causes

1. Connection not enabled for the application (most common). Connections are per-app opt-in.
2. Social connection missing its own keys: Google/GitHub/etc need a client id/secret in the connection settings; without them the connection stays inert.
3. Organization login: org logins only show connections enabled on the ORGANIZATION. App-level enablement is not enough.
4. Identifier-first flow: the button appears only after the user types an email whose domain routes to the social connection (home realm discovery). This is by design in identifier-first.
5. Display configuration: the new Universal Login shows social buttons based on enabled connections automatically; custom HTML can hide them.

Confirm

• Application > Connections: is the social connection toggled on? If not, found it.
• Authentication > Social > the connection: are provider keys filled in and the connection enabled at tenant level?
• For orgs: Organizations > your org > Connections: enabled there?
• Tenant logs: a login attempt with connection set to the social connection failing means the app tried it but it is not enabled.

Fix

Enable the connection in all three places that apply (tenant, application, organization), fill in provider keys, save.

Verify

Incognito login page shows the button; complete a full social login and confirm the success event names the social connection.

When to use this

• You are seeing this exact error message; match the block above, not just part of it.
• The failing call matches the scenario in the title: Social button missing on login.
• You want the fastest verified fix before digging through logs.

When not to use this

• Your error text differs from the block above; close cousins often have different causes.
• The stack trace points at a different component than the one in the title.
• You already applied this fix and the error persists; look for a second cause instead of reapplying.

Compatibility

• Not pinned to a specific version; follows current Social behavior.

Auth0's connection docs describe per-application connection enablement. Organization connection enablement is in the Organizations docs. Verified against live docs 2026-09-26.