Azure Function App Flex Consumption migration fails with ServerFarmCreationNotAllowed

Question

Azure Function App Flex Consumption migration fails with ServerFarmCreationNotAllowed

Pontem 0

I am trying to migrate an existing Linux Consumption Azure Function App to Flex Consumption, but the migration fails after the app passes the eligibility check.

I need to migrate this Function App from Linux Consumption to Flex Consumption so that I can use a newer Python version (3.13).

Debugged and confirmed this potential reasons:

Microsoft.Web or Microsoft.App wasn’t fully registered. (checked both are registered)
The subscription offer is still effectively restricted. (canada central is not restricted)
An Azure Policy blocks plan creation. (confirmed there's no policy that blocks the creation)

Command I ran

az functionapp flex-migration start \
  --source-name "<source-function-app>" \
  --source-resource-group "<source-resource-group>" \
  --name "<new-flex-function-app>" \
  --resource-group "<target-resource-group>"

Result

The app passes the eligibility check:

Validating that the app '<source-function-app>' is eligible for Flex Consumption migration...
Source app '<source-function-app>' is eligible for Flex Consumption migration.

Then creation of the new Flex Consumption Function App fails:

Creating Flex Consumption function app '<new-flex-function-app>' in resource group '<target-resource-group>'...
Using source app's storage account '<source-storage-account>' for function app '<new-flex-function-app>'
There was an error creating the Flex Consumption function app. Please address the issue and try again.
The subscription 'ee8ce930-...-484a95bddbfa' is not allowed to create or update the serverfarm.

Azure troubleshooting detector output

The Azure Portal detector shows multiple occurrences of:

Detected SubscriptionNotAllowedToCreateOrUpdateServerfarm

Example 1:

Resource: ServerFarm - <serverfarm-name-1>
Last Error Timestamp: 2026-06-08 16:41:33
Last Error CorrelationId: 507ed0d3-564e-4f04-a278-f896d319268d
Total Number of Occurrences: 4
Error Message: The subscription 'ee8ce930-...-484a95bddbfa' is not allowed to create or update the serverfarm.

Not sure whether this subscription is blocked from creating Flex Consumption serverfarms in Canada Central, or whether there is a backend subscription restriction/quota/policy preventing Microsoft.Web/serverfarms creation?

We would like to migrate this Function App to Flex Consumption so it can support the required newer Python version.

Pravallika KV 16,610 Reputation points Microsoft External Staff Moderator

2026-06-08T19:08:52.5166667+00:00
Hi @Pontem ,

Thanks for reaching out to Microsoft Q&A.

“The subscription … is not allowed to create or update the serverfarm.”

/ Portal detector: Detected SubscriptionNotAllowedToCreateOrUpdateServerfarm

This error usually means even though your app is “eligible” for Flex Consumption migration, the target resource creation is blocked at the platform/subscription level. In other words, the problem is likely not your Function App configuration or your migration command it’s that your subscription is restricted from creating/updating the underlying App Service plan/serverfarm that Flex Consumption uses.

What to try next (based on provided guidance)

Confirm you’re using the latest tooling The docs recommend using the latest Azure CLI/Az.Functions modules for creation/migration tooling issues. (It won’t directly fix a “subscription not allowed” backend restriction, but it’s a quick hygiene step.)

Create/target in a fresh resource group One of the troubleshooting sections notes that SKU/plan-related issues can be caused by how resources are mapped within an existing resource group, and recommends creating the plan in a new resource group.

So, even if your target RG is “fine”, try creating the Flex app in a new resource group (and rerun the migration).

Check for subscription-level limitations/allow-list Your migration attempt is failing during serverfarm creation. Based on the message, this is most consistent with a subscription offer / backend restriction / quota-like enforcement that blocks serverfarm creation for that subscription.

You mentioned Canada Central isn’t restricted, but the error is explicitly about the subscription not being allowed to create/update serverfarm, so region alone may not be the determining factor.

Follow-up questions:

Are you able to create a brand-new Flex Consumption Function App directly (not via migration) in the same region/subscription?

What role do you have on the subscription/resource group (Owner/Contributor/etc.)?

When you rerun the migration, have you tried specifying the target in a different/new resource group?

Can you paste the full CLI error output with --debug (or at least the verbose logs) and/or the failed deployment correlation ID from the portal?

What are the source and target Function runtime versions you’re targeting (especially for Python 3.13) and the Linux Consumption app’s current runtime stack details?

1 answer

Your answer

Answer 1

@Pravallika KV Thank you for your response, these are the answers:

I tried it but I cannot create a new flex consumption app (not in cli migration) - yes both in the same region and subscription.
The role is Owner
No, unfortunately the project should only be in the same resource group and subscription.
below are the full --debug error output
Linux Consumption app’s current runtime stack is Python v3.11

cli.azure.cli.command_modules.appservice.custom: There was an error creating the Flex Consumption function app. Please address the issue and try again.
cli.azure.cli.core.azclierror: Traceback (most recent call last):
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/core/commands/__init__.py", line 789, in _run_job
    result = cmd_copy(params)
             ^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/core/commands/__init__.py", line 335, in __call__
    return self.handler(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/core/commands/command_operation.py", line 120, in handler
    return op(**command_args)
           ^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/command_modules/appservice/custom.py", line 1278, in migrate_consumption_to_flex
    create_functionapp(cmd, resource_group, name, storage_account, flexconsumption_location=source.location,
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/command_modules/appservice/custom.py", line 8507, in create_functionapp
    raise ex
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/command_modules/appservice/custom.py", line 8405, in create_functionapp
    plan_info = create_flex_app_service_plan(
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/command_modules/appservice/custom.py", line 7788, in create_flex_app_service_plan
    poller = client.app_service_plans.begin_create_or_update(resource_group_name, name, plan_def)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/core/tracing/decorator.py", line 119, in wrapper_use_tracer
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/mgmt/web/v2024_11_01/operations/_app_service_plans_operations.py", line 1502, in begin_create_or_update
    raw_result = self._create_or_update_initial(
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/mgmt/web/v2024_11_01/operations/_app_service_plans_operations.py", line 1401, in _create_or_update_initial
    raise HttpResponseError(response=response, model=error, error_format=ARMErrorFormat)
azure.core.exceptions.HttpResponseError: Operation returned an invalid status 'Forbidden'
Content: {"Code":"Forbidden","Message":"The subscription 'ee8ce930-9386-4f0d-832f-484a95bddbfa' is not allowed to create or update the serverfarm.","Target":null,"Details":[{"Message":"The subscription 'ee8ce930-9386-4f0d-832f-484a95bddbfa' is not allowed to create or update the serverfarm."},{"Code":"Forbidden"},{"ErrorEntity":{"ExtendedCode":"70001","MessageTemplate":"The subscription '{0}' is not allowed to create or update the serverfarm.","Parameters":["ee8ce930-9386-4f0d-832f-484a95bddbfa"],"Code":"Forbidden","Message":"The subscription 'ee8ce930-9386-4f0d-832f-484a95bddbfa' is not allowed to create or update the serverfarm."}}],"Innererror":null}
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/usr/lib64/az/lib/python3.12/site-packages/knack/cli.py", line 233, in invoke
    cmd_result = self.invocation.execute(args)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/core/commands/__init__.py", line 677, in execute
    raise ex
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/core/commands/__init__.py", line 820, in _run_jobs_serially
    results.append(self._run_job(expanded_arg, cmd_copy))
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/core/commands/__init__.py", line 812, in _run_job
    return cmd_copy.exception_handler(ex)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/command_modules/appservice/commands.py", line 46, in _ex_handler
    raise ex
knack.util.CLIError: The subscription 'ee8ce930-9386-4f0d-832f-484a95bddbfa' is not allowed to create or update the serverfarm.
cli.azure.cli.core.azclierror: The subscription 'ee8ce930-9386-4f0d-832f-484a95bddbfa' is not allowed to create or update the serverfarm.
az_command_data_logger: The subscription 'ee8ce930-9386-4f0d-832f-484a95bddbfa' is not allowed to create or update the serverfarm.
cli.knack.cli: Event: Cli.PostExecute [<function AzCliLogging.deinit_cmd_metadata_logging at 0x7fea8a069440>]
az_command_data_logger: exit code: 1
cli.__main__: Command ran in 26.621 seconds (init: 0.067, invoke: 26.555)
telemetry.main: Begin splitting cli events and extra events, total events: 1
telemetry.main: Finish splitting cli events and extra events, cli events: 1
telemetry.save: Save telemetry record of length 4345 in cache file under /home/pontem/.azure/telemetry/20260608192343142
telemetry.main: Begin creating telemetry upload process.
telemetry.process: Creating upload process: "/usr/bin/python3.12 /usr/lib/az/lib/python3.12/site-packages/azure/cli/telemetry/__init__.py /home/pontem/.azure /home/pontem/.azure/telemetry/20260608192343142"
telemetry.process: Return from creating process 1154
telemetry.main: Finish creating telemetry upload process.

and these are the issue log in portal:

Detected SubscriptionNotAllowedToCreateOrUpdateServerfarm for ServerFarm - asp-pontem-644e

Description - The subscription xx is not allowed to create or update the serverfarm Recommended Action - If issue persists, please contact support with the timestamp and correlationId from Activity Logs or Deployment History Last Error TimeStamp -2026-06-08 16:41:33 Last Error CorrelationId - 507ed0d3-564e-4f04-a278-f896d319268d Total Number of Occurrences - 4 Error Message - The subscription 'ee8ce930-...-484a95bddbfa' is not allowed to create or update the serverfarm.

Detected SubscriptionNotAllowedToCreateOrUpdateServerfarm for DeploymentValidation - Microsoft.Web-FunctionApp-Portal-3abb8ed9-8d89

Description - The subscription xx is not allowed to create or update the serverfarm Recommended Action - If issue persists, please contact support with the timestamp and correlationId from Activity Logs or Deployment History Last Error TimeStamp - 2026-06-08 16:47:17 Last Error CorrelationId - 68172f92-1bf2-4a39-aafb-e90afb36e009 Total Number of Occurrences - 1 Error Message - The template deployment 'Microsoft.Web-FunctionApp-Portal-3abb8ed9-8d89' is not valid according to the validation procedure. The following resource provider(s) - 'Microsoft.Web/serverFarms (2024-11-01)' reported preflight validation errors. Tracking id is '05ecfec8-b006-4407-bdcb-2970a3d61cef'. See inner errors for details. Error code:ServerFarmCreationNotAllowed message:The subscription 'ee8ce930-...-484a95bddbfa' is not allowed to create or update the serverfarm.

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Azure Function App Flex Consumption migration fails with ServerFarmCreationNotAllowed

Command I ran

Result

Azure troubleshooting detector output

1 answer

Detected SubscriptionNotAllowedToCreateOrUpdateServerfarm for ServerFarm - asp-pontem-644e

Detected SubscriptionNotAllowedToCreateOrUpdateServerfarm for DeploymentValidation - Microsoft.Web-FunctionApp-Portal-3abb8ed9-8d89

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