Umbraco Forms 10.2.0. Null references when using "Send form to url"

[AlexanderWagner82]

Last Thursday I upgraded my clients site from Umbraco.Forms 10.1.3 to 10.2.0 and they reported that their "Send form to url"-workflows stopped working. When looking in the log I got this stack trace:

Form workflow "SendtoPardot" failed on "Submitted" of Record with Unique ID "27d0ae08-c257-4e4b-97fe-91bf38210a42" from the Form named "Webinar" with Unique ID "fc34062e-20d9-4d03-b13d-78bedb8c9cfa"

System.NullReferenceException: Object reference not set to an instance of an object. at Umbraco.Forms.Core.Providers.WorkflowTypes.PostToUrl.AddFieldMappings(NameValueCollection values, List1 mappings, Record record) at Umbraco.Forms.Core.Providers.WorkflowTypes.PostToUrl.Execute(WorkflowExecutionContext context) at Umbraco.Forms.Core.WorkflowType.ExecuteWorkflow(WorkflowExecutionContext context, IWorkflow workflow) at Umbraco.Forms.Core.Services.WorkflowExecutionService.ExecuteWorkflow(WorkflowType type, Record record, Form form, FormState state, IWorkflow workflow) at Umbraco.Forms.Core.Services.WorkflowExecutionService.ExecuteWorkflows(List1 workflows, Record record, Form form, FormState state)

Reverting to Umbraco.Forms 10.1.3 solved the problem, and this was on workflows that's been there since before the upgrade (I haven't tried with a new workflow since time to solve it was of the essence.

Steps to reproduce:

1. Create new form and add a "Send form to url" - workflow
2. Fill out the necessary input fields (see image below).
3. Send the form. You should get an error in the log.

[AndyButland]

Thanks for letting us know about this. I've been able to replicate and found the bug, which, as you say, was introduced in 10.2. We'll get this fixed for the next patch release.