Merge pull request #7069 from umbraco/cms/16-breaking-changes

Further details of 16 breaking changes

Author: sofietoft

16/umbraco-cms/fundamentals/setup/upgrading/version-specific/README.md

@@ -31,6 +31,26 @@ When upgrading to Umbraco 16, any data types using TinyMCE will be migrated to u
 
 To continue to use TinyMCE, a third-party package must be installed prior to the upgrade. This will disable the migration and allow you to continue with TinyMCE.
 
+**Updated dependencies**
+
+As is usual for a major upgrade, the dependencies Umbraco takes have been updated to their latest, compatible versions. This had little impact on the code of Umbraco itself, so we don't expect this to affect upgraded customer projects.
+
+The specific dependency updates made for Umbraco 16 can be found in these PRs: for [server-side](https://github.com/umbraco/Umbraco-CMS/pull/19117) and [client-side](https://github.com/umbraco/Umbraco-CMS/pull/19121) libraries.
+
+**Other breaking changes**
+
+Other than the TinyMCE removal, breaking changes are minimal in Umbraco 16. On the server side, changes are limited to removing already obsolete constructors and methods.
+
+Client-side there are a few things to look out for if you've built extensions to the backoffice:
+
+- When consuming contexts, an `undefined` response will be resolved when the context can't be provided or the host is disconnected. See [PR 19113](https://github.com/umbraco/Umbraco-CMS/pull/19113) for more information.
+
+- Similarly, consuming a context as a promise can result in a promise rejection and getting a context can result in an undefined response. See [PR 18611](https://github.com/umbraco/Umbraco-CMS/pull/18611) for more information.
+
+- When making calls to retrieve data from the server, if you used either of Umbraco's helper methods `tryExecute` or `tryExecuteAndNotify`, then you need to adjust your code slightly. `tryExecuteAndNotify` is obsolete, and `tryExecute` takes the 'host' as the first argument. See [PR 18939](https://github.com/umbraco/Umbraco-CMS/pull/18939) for more information.
+
+The full details of breaking changes can be found from [this list of labelled PRs](https://github.com/umbraco/Umbraco-CMS/pulls?q=is:pr+label:category/breaking+is:closed+label:release/16.0.0).
+
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