Tiger no longer supports AFP over AppleTalk. (Although AppleTalk printing is still supported.)
This means Tiger is incompatible with share points shared by file servers pre-Mac OS 8.6.
See Apple KB article 301183
Apple Filing Protocol (AFP) service is known by several names, including File Sharing, Personal File Sharing, AppleShare, and Apple File Service. Some AFP servers can only share over the AppleTalk protocol; they don’t offer sharing over TCP/IP, which is now the preferred protocol. If you try to connect to an AppleTalk-only AFP server from a Mac OS X 10.4 Tiger computer, this message will appear:
“Connection failed. This file server uses an incompatible version of the AFP protocol. You cannot connect to it.”
This happens because Tiger no longer supports connecting to AFP over the AppleTalk protocol.
As a solution, enable the TCP/IP protocol on the AFP server if it offers this option. If no TCP/IP option is available, connect to the Tiger computer from the computer that is the AppleTalk-only AFP server (instead of trying to connect from the Tiger computer to connect to the older computer). This method works because AppleShare client software on the older computer can connect to a Tiger computer over TCP/IP, even if it can’t offer service over TCP/IP.
This may also affect third-party AFP server products. Be aware that some affected AFP servers have a TCP/IP option, but others don’t.
Some AFP services that do not have a TCP/IP option include Personal File Sharing in Mac OS 8.6 and earlier, and the AppleShare server suite. Some AFP services that do have a TCP/IP option include Mac OS 9 File Sharing, and the AppleShare IP server suite.