> For the complete documentation index, see [llms.txt](https://docs.umbraco.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.umbraco.com/umbraco-forms/upgrading/version-specific.md).
# Version Specific Upgrade Notes
Version specific documentation for upgrading to new major versions of Umbraco Forms.
This article provides specific upgrade documentation for migrating to Umbraco Forms version 18.
{% hint style="info" %}
If you are upgrading to a minor or patch version, you can find the details about the changes in the [Release Notes](/umbraco-forms/release-notes.md) article.
{% endhint %}
## Version Specific Upgrade Notes History
Version 18 of Umbraco Forms has a minimum dependency on Umbraco CMS core of `18.0.0`. It runs on .NET 10.
### Date formats in workflows and exports
This change was introduced in version 18.2.0. It affects you if you upgrade from an earlier version 18 release. It also affects you if you upgrade to version 18 from version 17.5.0 or earlier.
A date value used to be written using whichever culture happened to be active. That was often not the culture the entry was submitted with. A month-first date such as `07/05/2027` could then be read back as the wrong day: 7 May instead of 5 July. Date values are now formatted for whoever reads them.
Every example in the table is the same submitted value: 5 July 2027 at 14:03, from an entry submitted in `en-GB` on a server running `en-US`.
| Destination | Before | From 18.2.0 |
| ------------------------------------------------ | -------------------------------------------------------------------------- | ---------------------------------------------------------------- |
| Entries list and entry details | The stored, month-first string for a custom date field: `07/05/2027 14:03` | The culture the entry was submitted with: `05/07/2027 14:03` |
| CSV and Excel export | Month-first, whatever the entry's culture: `07/05/2027 14:03` | The culture the entry was submitted with: `05/07/2027 14:03` |
| Send Email, Send Email with Template, Slack | The server's culture when the workflow ran: `7/5/2027 2:03 PM` | The culture the entry was submitted with: `05/07/2027 14:03` |
| Post as XML, Send Form to URL | The server's culture when the workflow ran: `7/5/2027 2:03 PM` | ISO 8601: `2027-07-05T14:03:00` |
| Save as an XML file, Send XSLT Transformed Email | The server's culture when the workflow ran: `7/5/2027 2:03 PM` | ISO 8601: `2027-07-05T14:03:00` |
| Save as Umbraco Content Node | A formatted string, parsed back to a date: stored as 7 May 2027 | The date value itself, with no round trip: stored as 5 July 2027 |
{% hint style="warning" %}
Check any system that reads a date from one of these workflows. A receiving endpoint or an XSLT file that expects the old format needs updating. The `created` and `updated` elements in the record XML now also carry a `Z` suffix, marking them as UTC.
{% endhint %}
Two further points to be aware of:
* An export of a form with entries in more than one culture holds more than one date format in the same column.
* The Save as Umbraco Content Node workflow now stores a day-first date correctly. A date of `05/07/2027` from an `en-GB` entry is saved as 5 July, not 7 May.
See [issue #1773](https://github.com/umbraco/Umbraco.Forms.Issues/issues/1773) for details.
### Upgrading directly from Forms 17.5.0
This fix was introduced in version 18.1.1. It affects you if you upgrade directly from Forms 17.5.0 to an earlier version 18 release.
{% hint style="warning" %}
Versions 18.0.0 to 18.1.0 do not recognize the migration state that Forms 17.5.0 ends on. The upgrade fails at boot with `The migration plan "UmbracoForms" does not support migrating from state "0625d467-f048-4b5b-aa38-3d42fbfa8cd3"`.
{% endhint %}
Upgrade to version 18.1.1 or later instead. See [issue #1782](https://github.com/umbraco/Umbraco.Forms.Issues/issues/1782) for details.
### Upgrading directly from Forms 13.9.9
This fix was introduced in version 18.1.0. It affects you if you upgrade directly from Forms 13.9.9 to an earlier version 18 release.
{% hint style="warning" %}
Versions 18.0.0 to 18.0.6 do not recognize the migration state that the 13.9.9 security patch added. The upgrade fails at boot with `The migration plan "UmbracoForms" does not support migrating from state "6149738f-25bd-44ac-9c1d-d66bbe9d4e2b"`.
{% endhint %}
Upgrade to version 18.1.0 or later instead. See [issue #1772](https://github.com/umbraco/Umbraco.Forms.Issues/issues/1772) for details.
### UTC date handling
This fix was introduced in version 17.3.0. It affects you if you upgrade to version 18 from version 17.0, 17.1, or 17.2.
Version 17.0.0 included a migration (`MigrateSystemDatesToUtc`) that converted existing system dates to UTC. The application code still wrote new records using `DateTime.Now`, which is local server time. This left inconsistent timestamps on form entries, workflow audit trails, and entity metadata. Version 17.3.0 corrected the code that writes those dates.
{% hint style="warning" %}
Data written between v17.0.0 and the fix may contain local server timestamps instead of UTC. Upgrading to version 18 does not correct that data. A SQL script is provided below to correct it. The script runs on SQL Server only.
Take a database backup before you run it. Then set the three variables at the top of the script:
* `@TimeZone`: your server's Windows time zone name.
* `@UpgradeDate`: the date you first upgraded to v17.0.0. Rows created before this date were already converted to UTC.
* `@FixDate`: the date you first deployed a version that includes the fix. That is v17.3.0 or newer, or any version 18 release. Rows created on or after this date are already UTC and must not be shifted again.
The script writes a marker to `umbracoKeyValue` when it completes. On a second run it reports the marker and exits without changing any rows.
The script also clears the affected days from the analytics summary tables. The background task rebuilds those days from the corrected entries on the next application start. Confirm the rebuild under **Settings** > **Health Check** > **Forms** > **Analytics Processing**.
The script excludes the `UFRecordDataDateTime` table, as those values represent user-entered dates that should not be shifted.
The original `MigrateSystemDatesToUtc` migration contained a duplicate conversion for `UFPrevalueSource`. The Created and Updated columns were converted twice. This has been fixed, but sites that ran v17.0 to v17.2 may have double-converted PrevalueSource dates that require manual correction.
{% endhint %}
{% file src="/files/TMxqiSD9yOMpMTnK8ryW" %}
Corrects historical data written with local server time instead of UTC. Set the time zone and both cutoff dates before running.
{% endfile %}
### Storage method for tracking rendered forms
This change was introduced in version 14. It affects you if you upgrade directly from version 13 to version 18.
In version 13, Forms tracked the forms rendered on a page using `TempData`. From version 14 onwards, the default value of the `TrackRenderedFormsStorageMethod` configuration option is `HttpContextItems`.
If your template renders form scripts using a custom snippet that reads the rendered form IDs from `TempData`, the snippet no longer finds them. As a result, the form scripts and any assets registered by custom field types stop rendering.
{% hint style="warning" %}
The scripts fail silently. Forms still submit, but conditional logic, field behaviors, and custom field type assets are missing from the page.
{% endhint %}
To resolve this, choose one of the following options:
* Update your snippet to read the rendered form IDs from `HttpContext.Items`.
* Use the `` tag helper, which respects the configured storage method.
* Set `TrackRenderedFormsStorageMethod` back to `TempData` to keep the version 13 behavior.
For the updated snippets and the tag helper, see the [Rendering Forms Scripts](/umbraco-forms/developer/rendering-scripts.md) article. For the configuration option, see the [Configuration](/umbraco-forms/developer/configuration.md#trackrenderedformsstoragemethod) article.
## Legacy version specific upgrade notes
You can find the version specific upgrade notes for versions out of support in the [Legacy documentation on GitHub](https://github.com/umbraco/UmbracoDocs/blob/umbraco-eol-versions/11/umbraco-forms/installation/version-specific.md).
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:
```
GET https://docs.umbraco.com/umbraco-forms/upgrading/version-specific.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.