Bicep compiler and linter messages

Errors stop the build; warnings don't — and the type checks are warnings. A file with BCP035, BCP036 or BCP037 compiles to JSON and deploys, then Azure refuses the resource. Treat type warnings as errors. Each message ends with a link, https://aka.ms/bicep/core-diagnostics#BCPnnn (or …/linter-diagnostics#<rule>). The wording below is from Bicep CLI 0.48.1; Microsoft's page writes some of it with contractions ("isn't" for "is not").

Types and properties (warnings)

Message	Cause → fix	Check
`Warning BCP035: The specified "resource" declaration is missing the following required properties: "sku".`	A required property is missing for that type and API version	The resource's reference page for that API version
`Warning BCP036: The property "<p>" expected a value of type "bool \	null" but the provided value is of type "'yes'".`	Wrong type: a string for a bool, an object for an array	Fix the literal or the parameter's type
`Warning BCP037: The property "<p>" is not allowed on objects of type "<Type>". Permissible properties include …`	Misspelt or misplaced property (often under `properties:` vs top level)	The permissible list in the message
`Warning BCP053: The type "<Type>" does not contain property "<p>". Available properties include …`	Reading an output property that doesn't exist	The available list in the message
`Warning BCP073: The property "id" is read-only. Expressions cannot be assigned to read-only properties.`	Setting a read-only property; remove it	—
`Warning BCP081: Resource type "<type>@<version>" does not have types available. Bicep is unable to validate resource properties prior to deployment…`	The API version is mistyped, or newer than this Bicep build's type library (storage `2026-09-01` with 0.48.1). Nothing in that resource is checked. Use a version Bicep knows	Build a one-resource file with candidate versions until BCP081 disappears
`Warning BCP333: The provided value (whose length will always be less than or equal to 1) is too short …` (and BCP334)	A literal fails the type's length limits, for example a storage name under 3 characters	The name rules for that type
`Warning BCP318` / `BCP321`	A value that may be null at deployment start. Use the safe-access operator `.?` with a default (`??`), or `!` if you know it isn't null	—

Names, scopes and timing (errors)

Message	Cause → fix	Check
`Error BCP057: The name "<n>" does not exist in the current context.`	Undeclared symbol or a typo	—
`Error BCP120: This expression is being used in an assignment to the "name" property of the "<type>" type, which requires a value that can be calculated at the start of the deployment. Properties of <sym> which can be calculated at the start include "apiVersion", "id", "name", "type".`	`name`, `scope`, `parent` and loop counts can't depend on runtime values such as another resource's endpoints. Derive them from parameters or `uniqueString()`	The properties listed in the message
`Error BCP135: Scope "<s>" is not valid for this resource type. Permitted scopes: "<p>".`	The resource can't be deployed at the file's `targetScope` (a storage account in a subscription file, a resource group in a group file). Move it into a module with `scope:`, or change `targetScope`	`targetScope` at the top of the file
`Error BCP134: Scope "<s>" is not valid for this module. Permitted scopes: "<p>".`	The module's own `targetScope` doesn't accept that `scope:` value	The module file's `targetScope`
`BCP139`, `BCP165`	A resource's (computed) scope differs from the file's: deploy it through a module	—
`Error BCP004: The string at this location is not terminated due to an unexpected new line character.`; `Error BCP064: Found unexpected tokens in interpolated expression.`	Broken quoting or `${…}` interpolation	The line and column in parentheses

Linter rules agents trip

Rule (warning)	Cause → fix
`secure-parameter-default`: `Secure parameters should not have hardcoded defaults (except for empty or newGuid()).`	Remove the default from the `@secure()` parameter; pass it at deploy time or with `getSecret`
`outputs-should-not-contain-secrets`: `Outputs should not contain secrets. Found possible secret: …`	Outputs are stored in deployment history in plain text. Don't output keys or connection strings: output the resource ID and read secrets at runtime
`no-hardcoded-env-urls`: `Environment URLs should not be hardcoded. Use the environment() function…`	Replace `management.azure.com` and similar with `environment().resourceManager` and friends
`no-unused-params`, `no-unused-vars`, `no-unused-existing-resources`	Remove them
`no-unnecessary-dependson`	Drop `dependsOn` already implied by a symbolic reference; unneeded dependencies slow deployments and can create cycles
`use-recent-api-versions`	Off by default; when enabled it flags API versions older than two years

Linter rule levels are set per repository in bicepconfig.json (analyzers.core.rules.<rule>.level: off, info, warning, error). Microsoft lists the type codes as "Error/Warning": against resource types they're warnings because a type definition can be inaccurate (the message asks you to report it). So fail your CI on them yourself: bicep build main.bicep 2>&1 | grep -E 'BCP0(35|36|37|53|73|81)' && exit 1.

When none of these fits

Open the link at the end of the message. Then confirm the API version exists for the type: az provider show --namespace <ns> --query "resourceTypes[?resourceType=='<type>'].apiVersions".