Action in a subflow not executing, but status showing as 'Completed'

[sd2097]

Hello devs,

I have come across a strange issue in flow designer. So, I have created subflow, and there is a custom action being called in the subflow, for each of the records being looked up. Suppose there are 3 records in the lookup action, the subflow will be executed 3 times.

I am executing the flow with a script. Even though the flow is executing, and the look up record action is also returning 1 record (as expected), the action is not executing at all.

One of the reasons that I could think of, is the error that I am getting when I am loading the steps of the subflow execution (please see the screenshot attached).

For context, I am looking up attachment records with Sys_Ids.

PS- Also, when I am running a test execution for the subflow, the result is the same.

This is turning out to be a major blocker, so any help would be appreciated.

Thanks

[Ankur Bawiskar]

@sd2097 

it clearly says some access issue.

Ensure Run as -> System user for the custom flow action and then test

If my response helped please mark it correct and close the thread so that it benefits future readers.

[sd2097]

Hi Ankur,

Thanks for your response. I did try with both 'User who initiates session', and 'System User', but the issue is still the same.

Thanks

[M Iftikhar]

Hi @sd2097 ,

This usually isn’t your flow logic that’s broken, but permissions / scope issues.

To fix this, you can try the following:

1. Check sys_attachements table ACLs

   • Make sure the user/role running the flow (e.g., system, flow_operator, or your integration user) has read access.

2. Check App Scope restrictions

   • If your custom action is in a scoped app, ServiceNow may block access to system tables like sys_attachment.

   • Go to System Applications > Application Cross Scope Access

   • Look for entries allowing Read on sys_attachment. If missing, add one.

3. Check the Flow runtime user

   • Make sure Run as -> System user for the custom flow action and then test

Thanks & Regards,
Muhammad Iftikhar
If my response helped, please mark it as the accepted solution so others can benefit as well.

[M Iftikhar]

Hi @sd2097 ,

Thank you for marking my reply as helpful.

If my response helped, please mark it as the accepted solution so others can benefit as well.

Thanks & Regards,
Muhammad Iftikhar