Is there any way to install version 2.5.9 32-bit?

[Ciccotti]

If the answer is yes, what changes do I need to make?

[mrotteveel]

I believe the answer is no. Why do you care if it is 32-bit or 64-bit?

[Ciccotti]

I use an old database, with 32-bit DLLs

[jacobalberty]

@Ciccotti so to be clear you're looking for 32 bit x86 right?

[arvanus]

Do you know that the bitness of the client is totally unrelated with the server?
You could have an 64bits server working perfectly with 32bit clients as long as the clients are using the correct 32bits dll

[mrotteveel]

@arvanus I think the OP is referring to UDF DLLs, which must match the bitness of the server.

[mrotteveel]

Though that wouldn't work either, because the Firebird Docker images are Linux, not Windows.