Problem

Cubase and Nuendo cannot launch because the application gets stuck on the loading screen at "Initializing: All MIDI Inputs."

Background

Microsoft recently started the rollout of new MIDI implementation (incl. MIDI 2.0) for Windows 11 24H2 and 25H2: 
Making music with MIDI just got a real boost in Windows 11

Unfortunately, this has led to a series of issues with certain MIDI devices and hardware configurations, where the MIDI services cannot be properly initialized. As a result, applications such as Cubase and Nuendo may become stuck during the initialization process.

Microsoft provides a regularly updated list of known issues and workarounds here: Windows MIDI Services rollout – known issues and workarounds

Solution

Microsoft started rolling out a Windows update on April 30, 2026, that addresses this issue. Therefore, check whether Windows updates are available on your computer and ensure that you have installed the latest updates for Windows.

Learn more here:
Install Windows Updates

Note that this update is being released gradually over a 30-day CFR rollout (until the end of May). This means it may only become available on your system at a later time.

If the issue persists on your computer and no Windows update is available, contact Microsoft directly for further assistance via the Discord server provided by Microsoft: https://aka.ms/mididiscord