UI error management for reached maximum receivers number

[larrykind]

Proposal

When in a channel is set a maximum of receivers selectable and a whistleblower will select more receivers than that value, the UI will not manage the error at that time, and allows the whistleblower to continue to fill the questionnaire.
In that case instead, system should not allow the whistleblower to proceed to the questionnaire with a clear message to the whistleblower, like "maximum receiver number reached, please select a maximum of (N) receivers".

Motivation and context

Since this setting is a limitation for the wislteblower receiver selection, a managed error should be displayed at receiver selection time.
If the system allows the whistleblower to fill the questionnaire and it will receive the said red error, it couldn't go back to receiver selection: it has to fill again the questionnaire.

At "send" time whistleblower will get a red flag server error with an english only text, generally not understood by the whistleblower, report is not sent, and system could be perceived as "not working" by the whistleblower.