When creating a Timer Trigger function from the portal i receive Value cannot be null. (Parameter 'connectionString') error

Question

When creating a Timer Trigger function from the portal i receive Value cannot be null. (Parameter 'connectionString') error

Oli Goldsmith 1

When following the basic steps of creating a timer Trigger function within the Azure portal, i receive the error

Value cannot be null. (Parameter 'connectionString')

in the logs window within the Code + Test tab. I have no connection string set in my app settings nor do I currently need one, so im unsure of why I receive this error?

MikeUrnun 9,777 Reputation points Moderator

2020-11-12T05:49:08.713+00:00

Hi @Oli Goldsmith @Malcolm Young @NP

I'm unable to reproduce this issue. I have created the following TimeTriggered (.NET Core) Function in Portal and it's triggering every min with no issues.

Could you provide more details about your setup? Did you make changes in your function.json file after creating your function? Could you share your function app name?
MikeUrnun 9,777 Reputation points Moderator

2020-11-13T06:25:40.17+00:00

@Oli Goldsmith @Malcolm Young @NP Let me know if you're still encountering and observing this issue, if so, please share your Functions App name privately and we'll review the logs to try to identify the root cause.
Oli Goldsmith 1 Reputation point

2020-11-13T07:18:22.307+00:00

@MikeUrnun I ended up deleting the Function App and publishing the actual function which I was originally trying to get working from VS again and it suddenly worked, very strange.

But in answer to your question, I didn’t change the function.json at all, simply just created a timer trigger function through the portal following the docs steps and also had it set to fire every minute but with no luck. I will try and replicate and add details.
Malcolm Young 11 Reputation points

2020-11-13T11:36:48.39+00:00
trying to reproduce this, I followed these steps in the portal:

Create Function App - Node.js v12

Add function - use Timer Trigger template

go to Code + Test

click Test/run

click Run

Output shows 202 accepted, with no contentthe log panel opens, and shows the welcome message, but nothing else happens

click Run again

same output, with log message: 2020-11-13T11:34:50.998 [Information] Executing 'Functions.TimerTrigger1' (Reason='This function was programmatically called via the host APIs.', Id=5400a759-d9ae-473b-b75d-b936ebe96b8c)
2020-11-13T11:34:51.002 [Error] Executed 'Functions.TimerTrigger1' (Failed, Id=5400a759-d9ae-473b-b75d-b936ebe96b8c, Duration=2ms)Value cannot be null. (Parameter 'connectionString')
MikeUrnun 9,777 Reputation points Moderator

2020-11-13T17:32:27.827+00:00

@Malcolm Young Gotcha, let me know if you're able to consistently repro this. I just tried on NodeJS and didn't hit the issue:
MikeUrnun 9,777 Reputation points Moderator

2020-11-13T17:34:16.597+00:00

@Oli Goldsmith Okay, glad to hear that you're no longer hitting this issue. Let me know if run into it again and if you're able to consistently repro.

4 answers

Your answer

MikeUrnun 9,777 Reputation points Moderator

2020-11-12T05:49:08.713+00:00

Hi @Oli Goldsmith @Malcolm Young @NP

I'm unable to reproduce this issue. I have created the following TimeTriggered (.NET Core) Function in Portal and it's triggering every min with no issues.

Could you provide more details about your setup? Did you make changes in your function.json file after creating your function? Could you share your function app name?
MikeUrnun 9,777 Reputation points Moderator

2020-11-13T06:25:40.17+00:00

@Oli Goldsmith @Malcolm Young @NP Let me know if you're still encountering and observing this issue, if so, please share your Functions App name privately and we'll review the logs to try to identify the root cause.
Oli Goldsmith 1 Reputation point

2020-11-13T07:18:22.307+00:00

@MikeUrnun I ended up deleting the Function App and publishing the actual function which I was originally trying to get working from VS again and it suddenly worked, very strange.

But in answer to your question, I didn’t change the function.json at all, simply just created a timer trigger function through the portal following the docs steps and also had it set to fire every minute but with no luck. I will try and replicate and add details.
Malcolm Young 11 Reputation points

2020-11-13T11:36:48.39+00:00

trying to reproduce this, I followed these steps in the portal:

Create Function App - Node.js v12

Add function - use Timer Trigger template

go to Code + Test

click Test/run

click Run

Output shows 202 accepted, with no contentthe log panel opens, and shows the welcome message, but nothing else happens

click Run again

same output, with log message: 2020-11-13T11:34:50.998 [Information] Executing 'Functions.TimerTrigger1' (Reason='This function was programmatically called via the host APIs.', Id=5400a759-d9ae-473b-b75d-b936ebe96b8c)
2020-11-13T11:34:51.002 [Error] Executed 'Functions.TimerTrigger1' (Failed, Id=5400a759-d9ae-473b-b75d-b936ebe96b8c, Duration=2ms)Value cannot be null. (Parameter 'connectionString')
MikeUrnun 9,777 Reputation points Moderator

2020-11-13T17:32:27.827+00:00

@Malcolm Young Gotcha, let me know if you're able to consistently repro this. I just tried on NodeJS and didn't hit the issue:
MikeUrnun 9,777 Reputation points Moderator

2020-11-13T17:34:16.597+00:00

@Oli Goldsmith Okay, glad to hear that you're no longer hitting this issue. Let me know if run into it again and if you're able to consistently repro.

Answer 1

Malcolm Young 11

This also happens for me when I'm following https://learn.microsoft.com/en-us/azure/azure-functions/functions-create-scheduled-function

The same error happens with a .NET and NodeJS function.

Possibly related, although I couldn't see any way to follow the suggestions in that post?

I also found this post on Stack Overflow, but I couldn't fix things following the advice there.

Answer 2

NP 1

i m getting the same error when i am running powershell from Azure Timer function

Answer 3

Anonymous

I'm getting same error with .net Core Trigger function

Answer 4

For me the problem was solved by adding an Application setting (app config): name: "AzureWebJobsStorage", value: string specified in keys to the storage you want to use for your function app (connectionString). You can add this parameter in Settings/Configuration for function app in the portal.
Also, the connection for TimeTrigger in function.json was defined as: "connection": "AzureWebJobsStorage"
If you have this paramater AzureWebJobsStorage defined before you add a new function it will be suggested as connection in the function creation form. It did not work with some other string than "AzureWebJobsStorage" even if it was also defined in application settings in the same way. Don't ask me why...

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When creating a Timer Trigger function from the portal i receive Value cannot be null. (Parameter 'connectionString') error

4 answers

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