First try rebooting your computer. Sometimes this will reset things.
Some users are finding that their Windows system does not have a MIDI device installed. Check in BioExplorer | Preferences | Audio tab in Default MIDI Device. Microsoft GS Wavetable Synth used to be installed on Windows computers, but if it is not you will need to install a MIDI synthesizer. One we have found is CoolSoft VirtualMIDISynth: http://coolsoft.altervista.org/en/virtualmidisynth
1. Download and Install MIDISynth
You need to download the file and install (double-click on the setup file). During the installation take note of where the file is being installed (maybe Program files) to launch the application later.
2. Download SoundFont
Then scroll down the page to the section Sound Fonts. Select one or more to install and try. Or you can download a soundfont we have used, FluidR3_GM.sf2.
3. Add SoundFont
Launch the CoolSoft VirtualMIDISynth application. Click the green + button and browse to your Downloads folder and select the soundfont you just downloaded and click Apply and OK. If you do not know how to do this, your local computer expert can help.
4. Set as Default MIDI Device
Next, Set the default MIDI device in BioExplorer. In BioExplorer | Preferences | Audio select the Default MIDI Device.