Almost every module comes in two files. The module itself is either a Windows Executable (.exe) file or a Omniscope Script (.scp) file. It is usually accompanied by a small file with the .rvc extension. This file tells Omniscope exactly what devices the module can be used with.
When you click on any device in Omniscope, the program compares the device with the information in the various .rvc files. If the information matches, the module is included in Omniscope's list for that device. Therefore, if the .rvc file is missing then that module will not appear on any device's list.
You can always force Omniscope to run a module, even if the .rvc is missing or doesn't match. Simply click on the "Run Module Not Listed Here" button below the Device List, and select the module with the file selector. If the modules is targeted to a particular device then that device must be selected before you start the module.