[EPIC] Requires MAJOR version bump

Fixing these issues would break compatibility in MuseScore's external APIs, such as the plugin API or the MSCX file format.

• Such issues cannot be addressed until immediately prior to the release of MuseScore's next major version.
• If they are not ready in time for that version then they cannot be fixed until the following major version.

See Semantic Versioning for details.

Note: The following are not considered to break compatiblility:

• API changes that are handled gracefully (e.g. ignored) by previous versions of the program.
• Changes to MuseScore's UI or internal data structures (i.e. non-API changes).