* feat: add known editor issues

docs/known-issues.md

@@ -22,6 +22,37 @@ The `data` directory is located in the base directory of the backend.
 These files can be deleted while the server is running,
 however only if there are no actual running exercises.
 
+## Editor: The created definition is invalid
+
+### Issue
+
+Leaving the _Content_ field blank during the _Injects preparation_ phase results in the creation of invalid definitions.
+
+### Cause
+
+In this case, the _content_path_ in _injects.yml_ is set to a non-existing file.
+
+### Solution
+
+During the _Injects preparation_ phase in Editor, make sure to fill in the _Content_ field for all your injects.
+
+## Editor: Failed to update inject (ConstraintError)
+
+### Issue
+
+When clicking on _Save_ or _Save & Exit_ during the _Injects preparation_ phase, the following error is shown:
+
+![Failed to update information inject: ConstraintError: Unable to add key to index 'injectInfoId': at least one key does not satisfy the uniqueness requirements. ConstraintError: Unable to add key to index 'injectInfoId': at least one key does not satisfy the uniqueness requirements.](./images/editor-inject-preparation-error.png)
+
+### Cause
+
+When saving the prepared inject for the first time, the creation process triggers twice due to an error in code.
+Therefore, the code is trying to create an inject with the same key (id), triggering the constraint error.
+
+### Solution
+
+Ignore the error.
+
 ## Conclusion
 
 If you require further assistance, don't hesitate to report issues to us. The [Report issue](report-issue.md) page includes instructions on how to report bugs.