According to the message "Expected backup version less than or equal to 7. Found 9" this backup file was made by Firebird gbak version 2.5. You can restore it on any Firebird server version 2.5 or higher.

The errors you get trying to connect to database on MAC is not related to database format but to file system permissions (not necessarily for the database file itself, it may be problem with temporary files as well). You can solve them using remote connection string instead of embedded and/or adjusting permissions on involved files.

The error you get trying to connect to the database on PC imply that you simply copied the file from Mac which is no go because database file is platform-dependent. You can solve it by restoring the backup file on PC.

The error you get trying to restore Firebird backup using Interbase is caused by fact that Firebird and Interbase are different SQL servers even though they had common ancestor. You cannot solve it.

According to the message "Expected backup version less than or equal to 7. Found 9" this backup file was made by Firebird gbak version 2.5. You can restore it on any Firebird server version 2.5 or higher.

The errors you get trying to connect to database on Mac is not related to database format but to file system permissions (not necessarily for the database file itself, it may be problem with temporary files as well). You can solve them using remote connection string instead of embedded and/or adjusting permissions on involved files.

The error you get trying to connect to the database on PC imply that you simply copied the file from Mac which is no go because database file is platform-dependent. You can solve it by restoring the backup file on PC to create a suitable database.

The error you get trying to restore Firebird backup using Interbase is caused by fact that Firebird and Interbase are different SQL servers even though they had common ancestor. You cannot solve it.