> Firebird has been upgraded to version 3.0.0. It is unable to read back Firebird 2.5 data, so embedded firebird odb files created in LibreOffice version up to 5.2 cannot be opened with LibreOffice 5.3. Since a future version of firebird will have a backwards compatibility module, some future version of LibreOffice (embedding this future version of firebird) will also be able to open these older files.

> ODB files created by LibreOffice < 5.3 can be manually converted to LibreOffice 5.3 format by using Firebird 2.5 to convert the data to archive format, and replacing the database data within the ODB by the archive format version. To do this, install a stand-alone Firebird 2.5, and use its "gbak" tool to convert the file "database.fdb" to "database.fbk" within the odb file. Don't forget to remove the .fdb file.

I don't use this feature so I don't know how popular it is, but it seems like this could cause a lot of problems for people. They probably shouldn't have updated to Firebird 3.0.0 until they had an automated migration process in place, instead of instructing end users to manually convert their old files from the command line.