To analyze the issue further, please answer these questions:
- Is it just that particular instrument or sample that doesn't sound, or are all other samples in the module also affected?
- Does it only happen with specific samples? If so, please upload an example file.
- When you play the sample in question in the sample editor, does the playback marker (vertical line) still move even though you don't hear anything?
- When you play the sample in question in the sample editor, does the timer in the lower-right corner of the window still run?
- When you play the sample in question in the sample editor, what does the statistics field in View -> Setup -> Sound Card say?
- Are you using ASIO for audio playback in OpenMPT?