Upgrading to 0.5
Code compatible with 0.4 is expected to compile and run without modifications with 0.5.
There is a breaking change in code between 0.4 and 0.5.
IndexDefinition.Find has been renamend to
Data from 0.4 remains readable, but existing indexes are no longer readable so they will have to be rebuilt.
Copying all objects to a new collection will do the trick. It is even better to copy the data to a new collection-file and delete the previous one to save space.