My Firebird 2.5 data cannot be opened with LibreOffice 5.3
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.
Embedded firebird switched to Firebird's "archive" format, which is version and endianness independent, so this issue won't happen again.
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.