Background & Problem

From time to time, the JSON wikipage with the configuration might end up containing invalid configuration. This can happen during configuration schema changes, thanks to a bug or for other reasons. Currently, whenever that happens, the configuration form displays this error message:

This is unhelpful, as it (a) does not provide any information about where the issue is (b) it is impossible to fix the problem from the form.

Solution

When the editor encounters an invalid configuration, it should:

• explain where the issue is (where is the invalid data coming from, what the validation error is)
• give the user a choice between fixing the issue themselves (for example, by manually fixing the config within the JSON wikipage) and getting an empty form (=form filled in with default configuration) and re-configuring everything from scratch

While working on this problem, we need to keep the Configuration Store concept in (right now, the config is stored in JSON wikipages, but in the future, it might be somewhere else). This needs to be implemented in a sufficiently generic way to support different stores that might be implemented in the future.

Considering the first bullet point is easier to satisfy, we will work on this iteratively, and fulfilling the first bullet point is in scope for a subtask.