Dear all, I am using the alea libraries for an implementation of a monte carlo simulation. If I try to use the HistogramObservable as follows: measurements << alps::HistogramObservable<double>("MyObservable"); It compiles, it runs, but when it tries to write the hdf5 file either while checkpointing or when finished I get the following error: HDF5 Error writing path '/' on type 'N4alps9scheduler12MCSimulationE': HDF5 Error writing path '/simulation/results' on type 'N4alps13ObservableSetE': HDF5 Error writing path 'MyObservable' on type 'N4alps19HistogramObservableIdEE': HDF5 Error writing path '@size' on type 'j': Error in /Users/sebi/ALPS/include/alps/hdf5.hpp on 842 in set_attribute: unknown path: /simulation/results/MyObservable Regards, Sebastian -- Sebastian Huber Department of Condensed Matter Physics The Weizmann Institute of Science 76100 Rehovot Web: http://www.weizmann.ac.il/~huber Tel: +972 8 934 4258