问题
I've got two computers both running Firebird (let's called them A and B) and two database files (let's call them a.fdb and b.fdb), both copied to both computers. On B I get the message
b.fdb is not a valid database The other files work, on A both files work.
This would be easy to explain, if B was an older version, but it's a newer one (it was FB 2.1, and because of this problem I installed FB 2.5). The files a.fdb and b.fdb have ODS 11.1 and 10.1, respectively. It looks like new versions of FB wouldn't support ODS 10.1 anymore, which I can't believe. But I see no other explanation, can you?
回答1:
Try to make backup and restore of database.
回答2:
I had the same problem with an old database.
In my case even the gbak command presented the "is not a valid database". (I also tried with the FIX_FSS_METADATA option)
I found that if the database was created in an 32bits environment it can't be opened in one 64bits one.
So, what I had to do was: - Create a VM with a 32bits environment (in my case I created a VM with Windows XP) - Copy the database the this VM and make a backup using GBAK - Copy the backup file to my machine (64bits) - Run a restore using GBAK
After all this I could open the database again.
Hope it helps!
来源：https://stackoverflow.com/questions/4862392/firebird-2-5-reports-is-not-a-valid-database-although-it-is