Hello list, I have a bunch of XML files that have been serialized using Boost.Serialization (the standard XML archive) and were working fine until we upgraded to the boost trunk a few days ago (unfortunately, I can't tell exactly what repository revision were used to generate the archives, but I know they were custom builds of pre-release 1.37 trunk, and the file_version attribute in the XML is set to 4.) Also, we use MSVC9.0sp1 for building everything. As soon as we upgraded to the trunk, we started getting runtime exceptions (invalid archive format) on some of our larger files. I think I have tracked it down to an incompatibility between version 4 and version 5 files that the newer build fails to take into consideration, the details of which (as far as I could find out) follows. In our data structures there is an std::list of pointers to objects previously serialized in the same serialization operation (which means these repeated pointers are stored as a reference to the previous object and the data is not duplicated.) Using the old library, when this list was being serialized, apparently the "item_version" was not being written (only the "count" filed and the "item"s were.) The old library apparently didn't expect to read this either, so everything worked out nicely. The new library however, expects an "item_version" field and throws when it doesn't find one. As I trace into the serialization library, I can see that there is logic there for new libraries to be able to handle archive format changes through time. Now my question is whether this "discrepancy" is actually a bug in either the older or the new code, or failing to handle the format change is a bug, or this issue has already come up and been dealt with in some other way? (how?) I should also mention that it is quite probably that the problem be in our code, but I have no idea how. I would appreciate any help in locating it. Any pointers, help, clues and general wisdom is greatly appreciated. -yzt