Yokemate of Keyboards
Posts: 2159 from 2003/2/24
From: po-RNO
Maybe it should read more clearly everywhere, but NEVER modify anything from SYS:MorphOS/ aka MOSSYS: path. Except if you want to rename rexxsyslib.library :) Or if you are absolutely sure what you are doing.
Every dir found in MOSSYS: can be cloned to SYS: and you can add own stuff there. So, correct place for custom MUI classes is SYS:Classes/MUI/. Old installers made for Amiga may fail copying them there and it's usually needed to copy manually. Actually many programs are easier to install manually by copying needed libs to SYS:Libs, mui libs to sys:classes/mui etc. It's pretty obvious when you look directory structure on unpacked archives.
Whole MOSSYS: is replaced when you do automatic system update with every new MorphOS version. So, if you've made any modifications there, they will be lost.
You can use SYS:Tools/Snoopium program to find out if any files are missing when you start certain program. Run Snoopium, run program causing problems, look the log in Snoopium window and check if there's some file which can't be opened on any path it's trying. There will be fails logged, but it's ok until it can get one open for the asked file.