We noticed the same behavior that the Link Resolver TBB does not generate the right case for binaries type. It being generated as <tcdl:Link type="binary" ../>
instead of <tcdl:Link type="Binary" ../>
(note the lower case b instead of Uppercase B, tough one to catch). The REL TCDLTagRender is case sensitive and does not resolve the tcdl:link with lowercase type:binary and you will see the warning message in cd log files (assume you have log level set to warn or debug).
"WARN LinkTagRenderer - Link type does not exist."
The work around is to replace the output of lowercase binary
with the uppercase Binary
by introducing a new TBB. We included this as part of the TBB to resolve the RTF field binary link resolving for any multimedia linking like pdf, doc etc..
You do a string replace the lowercase binary with Binary as below in the TBB.
string output = package.GetValue(Package.OutputName);
output = output.Replace("type=\"binary\"", "type=\"Binary\"" );