@dannytaurus Keeps crashing apparently, didn't get much detail. He (or perhaps an AI he used) found the same solution as the other guy though:
Open Rhapsody and at the top open the Gear icon then the Plugin/Gear icon.
Click on the Troubleshooting tab right next to Processing at the top of that window.
In FL Studio 2026, Image-Line moved Use fixed size buffers into that Troubleshooting tab. Once you click it, you will see a toggle switch labeled Use fixed size buffers.
Turn that switch ON. If a warning popup appears asking to confirm, click OK/Yes.
In the Processing tab, turn Allow threaded processing OFF (click the orange light next to it so it goes dark). Disabling multithreading on this specific wrapper stops HISE-based plugins like Rhapsody from throwing buffer exceptions during playback.