The TomatoCart Core Team will test the coupon feature according to your report. If there is any issue in that part, it will be fixed in TomatoCart 1.1.8. In addition, once the team resolve any bug, a package about the bug will be added into www.tomatocart.com/downloads/bugs-packages.html.
So, the community users who are using the TomatoCart 1.1.x could download the bug packages to fix the bug before the Version 1.1.8 is released.
Thanks for your report. You are actually assisting the core team to make this software more stable and security.
The TomatoCart Core Team's goal is to continue to provide regular, frequent updates to TomatoCart community. Moreover, enhance the stability and security of TomatoCart project.