This is due to the OAK behavior which gives you a view on a certain
state within the repository, when a change is performed on the
repository, the change is performed against this base state and is
applied (merged) to the HEAD state.In case the state of the session
differs too much from the HEAD state the merge fails, and an OakMerge
exception is raised. This is due to other changes happening in the
repository, which could affect also the areas where your session wants
to perform its changes. Th...