Prevent program changes

You could change the properties of every module (src, dat) in read-only. In this way you can see inside it but not modify it.

There are several things one can do such as edit user rights. Unfortunately this is not straight forward on KSS before 8.5.

As mentioned, one can make modules read only.

Another option is to place programs into folder, make folder hidden and only expose calling program which is not hidden.

Trad the manual or explore menus

I have password protected the programs in the past.

Expert Mode to make any changes such as touching up points.

KRC4 Foundry Robots

that is also an option. it requires KUKA Encrypt package which is a paid option.

also this only prevents modification of the programs but users may still delete them.

usually people want to prevent any change (editing, touchup, renaming, moving...)

in KSS8.5.x and later, one can login as Admin and grant or restrict access to various things using menu Start-Up>Rights Management