In Reason 9 and later, and in Reason Essentials 9 and later, the Line 6 Guitar Amp and Line 6 Bass Amp devices have been removed and replaced by the included Softube Amp and Softube Bass Amp Rack Extension devices. The reason for this is technical and was necessary for us to be able to support future product development. If you open a "pre-version 9" Reason or Reason Essentials song which contains Line 6 devices, the following alert is shown:
If you click Open, all Line 6 Amp devices will be automatically replaced by Softube Amp devices: Line 6 Guitar Amp devices are replaced by Softube Amp devices and Line 6 Bass Amp devices are replaced by Softube Bass Amp devices. The Softube devices are also automatically set to Bypass mode. You can then enable the Softube Amp devices and tweak the sounds to your liking.
Alternatively, click Cancel and shut down Reason 9 (or later versions). Then, open your song in your "pre-version 9" Reason program. In the older Reason version, bounce your Line 6 tracks to audio files on disk. Then, open the song in Reason 9 and import the bounced audio files to the tracks in the song. This way, the tracks will sound exactly like in the older Reason version.