Added details of breaking changes for 17

[AndyButland]

📋 Description

Added details of breaking changes for Umbraco CMS 17.

Note when reviewing that this page is copied from the 16 version. The only changes made and that need reviewing are within the "Breaking Changes" section under the detail for "Umbraco 17" (currently lines 20 to 156).

As the 17 folder isn't populated yet, broken links will be reported.

📎 Related Issues (if applicable)

Populated from the following list of PRs with breaking changes for 17:
https://github.com/umbraco/Umbraco-CMS/pulls?q=is:pr+label:category/breaking+is:closed+label:release/17.0.0

✅ Contributor Checklist

I've followed the Umbraco Documentation Style Guide and can confirm that:

• Code blocks are correctly formatted.
• Sentences are short and clear (preferably under 25 words).
• Passive voice and first-person language (“we”, “I”) are avoided.
• Relevant pages are linked.
• All links work and point to the correct resources.
• Screenshots or diagrams are included if useful.
• Any code examples or instructions have been tested.
• Typos, broken links, and broken images are fixed.

Product & Version (if relevant)

CMS 17

Deadline (if relevant)

For publication on October 15, along with the 17 beta release.

📚 Helpful Resources

• 🧾 Umbraco Contribution Guidelines
• ✍️ Umbraco Documentation Style Guide

[eshanrnh]

@AndyButland, I've set up the v17 folders. Can you please resolve the merge conflict?

[AndyButland]

Yes, that's done now @eshanrnh.

[kjac]

I've updated the PR to include details for umbraco/Umbraco-CMS#20021

[github-actions]

The Link Checker found broken links in your PR.
Please review the following list:

Broken links found in: 13/umbraco-forms/release-notes.md

⚓ Anchor not found → 13/umbraco-forms/upgrading/version-specific.md#version-13 | Cannot find fragment

Broken links found in: 16/umbraco-forms/release-notes.md

⚓ Anchor not found → 16/umbraco-forms/upgrading/version-specific | Cannot find file

Broken links found in: 17/umbraco-cms/fundamentals/setup/upgrading/version-specific/README.md

⚓ Anchor not found → 17/umbraco-cms/customizing/extend-and-customize-editing-experience.md | Cannot find file

⚓ Anchor not found → 17/umbraco-cms/fundamentals/setup/upgrading/version-specific#umbraco-14 | Cannot find fragment

⚠ Unknown error → [522] http://issues.umbraco.org/issue/U4-6595 |#124; Rejected status code (this depends on your "accept" configuration): Unknown status code

⚠ Unknown error → [522] http://issues.umbraco.org/issue/U4-8031 |#124; Rejected status code (this depends on your "accept" configuration): Unknown status code

⚠ Unknown error → [522] http://issues.umbraco.org/issues/U4?q=Due+in+version%3A+7.6.0+Backwards+compatible%3F%3A+No+ |#124; Rejected status code (this depends on your "accept" configuration): Unknown status code

❌ 404 Not Found → https://docs.umbraco.com/umbraco-forms/installation/version-specific.md#version-4-to-version-6 | Rejected status code (this depends on your "accept" configuration): Not Found

❌ 404 Not Found → https://our.umbraco.com/Documentation/Reference/Querying/Udi | Rejected status code (this depends on your "accept" configuration): Not FoundFull Github Actions output

[eshanrnh]

Thanks for the PR, @AndyButland @kjac 🙌 The Pr looks great.

I've added a few suggestions to make the sentences clear and fixed the reported broken links as well 🤞

[AndyButland]

This didn't need merging and publishing yet @eshanrnh - was for Oct 15. No real problem though so no need to revert, but ideally it wouldn't be published yet.

[eshanrnh]

I've merged the changes since the v17 documentation site isn’t yet published or publicly accessible. As a result, the changes won't be visible to the public and are only available in GitHub/GitBook.

The v17 documentation site will be published and appear in the dropdown menu starting October 15 😊 Please let me know if anything appears visible before then 🙈