If you moved your libraries to an external SSD to save space, the pointer might be broken. Go to > Libraries/Paths inside EZdrummer 3.
The most common culprit is that EZdrummer 3 simply doesn't know where your MIDI folders are located. This often happens after moving files to an external drive. Open the EZdrummer 3 standalone app or your DAW plugin.
If you moved your libraries to an external SSD to save space, the pointer might be broken. Go to > Libraries/Paths inside EZdrummer 3.
The most common culprit is that EZdrummer 3 simply doesn't know where your MIDI folders are located. This often happens after moving files to an external drive. Open the EZdrummer 3 standalone app or your DAW plugin.