Is There a File Decoder To See Inside Files?
 

I need a file decoder to view files to see why my sub targets everything instead of just allies

Your gonna have to be way more detailed then that.
S3D will allow you to look at files but sounds like you have a different issue going on.

Basically theres something wrong with what my sub targets and it is targetting both axis and allied ships. For example if I start up a new career and toggle fire at will my sub will start shooting at schnellboats and type 34 destroyers. In this video I saw someone play around with stuff and their sub wasn't targetting axis ships at all and people are also telling me what my issue is is something they don't experience.

Theres something wrong with the Steam version of the game because my laptop which has a download from 3 years ago also experiences this issue.

Basically I don't know what files to look through but I wanna see if theres something among the files that directs what the player shoots at when fire at will is enabled or "teams"

IIRC, there is effectively a "bug" with the "automatic" shooting of your deck gun. The crew will fire on everything including your own allies, exept if you select a target to shoot at. But once this target is destroyed, the crew will automatically fire on the next nearer ship, even if it's a German ship.

Is there any kind of hotfix for it or a way to fix this bug?

No, AFAIK. Anyway, it's not a big problem I think, because you're supposed to be a lone hunter after all, isn't it?

I play with mainly single missions and I like to add in whatever so its an issue for me