This is required because the internal structure of arrays has been made more efficient. Even when your DLL does not use arrays, a recompile is required.
Of course, .oxo files which are part of this release need not be recompiled.
Note that you can see local variables when using the debugger to trace into .oxo files only if they have been compiled with debugging on (whic leads to slower code).
vecindex() now returns an empty matrix if no matches are found. It used to return -1 in that case.
has been renamed to diffpow()