Open a support ticket and I can take a look at it over TeamViewer.
Feel free to make a support ticket if you need help. then Pwizard can do a teamviewer session with you.
Are both the main game and the deep ocean DLC installed and using the Ubisoft platform (not Steam)? Could also be a scanner in your antivirus detecting the trainer modifying the game. Put the trainer in the exclusion list and disable any live/active/real time scanners or protection.
I think that both the main game and DLC are using the Ubisoft platform but maybe not as I did purchase and install them with Steam? As far as antivirus, I only have Windows 10, but I went into settings and turned off "real-time protection", "cloud-delivered protection", "automatic sample submission", and "tamper protection". That's all I could see to disable. I also added the trainer itself to the Exclusions list. When I start the trainer I get two script errors. On each one it asks if I want to continue running scripts and I just say Yes to both of them. Not sure if that has anything to do with it. I also noticed another user has this same problem over in the comments for the regular (non-DLC) version. Thanks!