IQAN6 project to IQAN5

Once a project file has been saved in a newer version, it is not possible to revert it back to an older one. 

But there might be a backup copy of the old version. 

Yep noticed that, but bu-file is also updated to version 6. (Multiple little program updates and saves.)
So now I'm in position that I have to manually rewrite the whole program?

You might understand that I'm not very pleased about this, but I take part of the blame.

I'm pretty sure that this might happen to others as well and  don't understand why there is so steep backward incompatibility.

I've had this issue as well. Luckily we were able to recover the version 5 project when a service tech accidentally saved over it in version 6. This was particularly an issue with early versions of IQANdesign6 when all IQAN project files would open in IQANdesign6. It's better now that IQANdesign Launcher opens projects in the version they were created in, but it's still a frustrating issue that comes up from time to time.

Not sure if there's anything that can be done about it, but it would be nice if there was a way to revert programs, particularly those that have modules that aren't supported in version 6.

Whatever machine you last sent the program to will have a version that can be recovered with IQAN 5 by "get application".

(Non-IQAN-related: you really should have daily and weekly backups of all your files outside your computer/network in case you get ransomware)

Feature request: make IQANdesign 6 popup a warning every time saving a file with unsupported modules inside (I have wasted a couple of hours on this aswell, having to go back to yesterdays backup).

What we have today is a confirmation dialog "Project will be updated", asking if one wants to create a backup copy of the old version. 

If you have answer Yes to this question there will be a backup copy of the original version in the folder. 

Example:

Backup copy (version 5.07) of filname.idsx

Maybe there is a need to make this dialog box more clear? 

The problem is that this dialog does not warn if you have modules in your project that will give errors in project check.

Maybe show a small red X and a warning "The following modules will not work in this version and need to be replaced"

I think the dialog could pop up every time you save until all old modules have been removed from the project.