Type: Known Issue
Category: Umbraco Forms > Upgrades & Breaking Changes
Tags: Umbraco Forms, v17 upgrade, custom workflow, workflow settings, setting view, MediaEntityPicker, media picker, property editor UI, empty picker, Forms 17.5

Product: Umbraco Forms
Version: 17 (affects upgrades from Umbraco 13)

Symptoms

After upgrading a solution from Umbraco 13 to Umbraco 17, a media setting on a custom Umbraco Forms workflow shows as an empty picker in the backoffice, even though a media item was selected before the upgrade.

Specifically:

The setting renders as a media picker with an empty drop zone, exactly as it looks when no value has ever been set.
No thumbnail, filename, or path is shown.
There is no error anywhere: nothing in the Umbraco log, nothing in the browser console, and no validation message.
Inspecting the network requests, the Forms media/by-path call returns 200 OK with a correct JSON payload describing the media item.

The last point is the giveaway. The stored value is intact and the API resolves it correctly — the picker simply doesn't display it.

Cause

From Umbraco Forms 14 onward, the user interface for a setting on a custom field, prevalue source, or workflow type is defined by an Umbraco property editor UI, set through the View property on the Setting attribute:

[Umbraco.Forms.Core.Attributes.Setting("Mail header photo", View = "Umb.PropertyEditorUi.MediaEntityPicker")]
public string MailHeaderPhoto { get; set; }

In Umbraco 13 the equivalent setting used the older File view. On upgrade, that setting resolves to Umb.PropertyEditorUi.MediaEntityPicker, which expects a different value format than the media file path stored by the v13 view. The picker cannot interpret the existing value, so it renders as though empty.

This is a confirmed bug in Umbraco Forms, not a problem with your implementation or your data.

Is my data at risk?

No. The value is still stored and still resolvable — this is a rendering problem in the backoffice only.

Because the value is intact, there is no need to write a custom migration or to run SQL against your databases to repair it. If you were considering either, hold off until the fix is available.

Status

A fix is expected in Umbraco Forms 17.6.0-RC, released on 6th August and the final release on 20th August; check the Umbraco Releases for availability.

Until then, the affected setting will appear empty in the backoffice after the upgrade.

What to check before you upgrade

If you maintain custom Forms field, prevalue source, or workflow types, it's worth auditing them before a v13 to v17 upgrade:

Find every custom type that inherits from WorkflowType, FieldType, or a prevalue source base class.
List the settings on each one, and note which View each setting uses.
Flag any setting that handled a file or media item in v13. Those are the ones affected by this issue.
Note the currently selected values before upgrading, so you can confirm them afterwards.

Settings work the same way across field, prevalue source, and workflow types, so the same symptom can appear on any custom type with a media setting — not only workflows.

Still having issues?

If a media setting on a custom Forms type is empty after upgrading and the behaviour does not match the description above — for example if you do see an error in the log or console, or the media/by-path request does not return 200 — that is likely a different problem. Contact Umbraco Support with the request details and any log output, or ask to talk to a human agent if you are already in a support conversation.

Media settings in custom Umbraco Forms workflows appear empty after upgrading from v13 to v17