I am opening from Open Airport, but I think I may have found the reason. In the save work folder the files were read only.
Don't know why? Maybe they always were.
Still trying to solve it.
For your information
ADE version 1.00 OK.
Installed ADEH 1.01 & SDE LIB 1.01.
When trying to load previous ADE files programme crashes.
Could not find file 'G:\Utilities for FSX\Airport Design Editor\EGVA_ADE_BOB.ade'.
at System.IO.__Error.WinIOError(Int32 errorCode...