With older versions of ConTeXt (including that in TL18) seeindex entries pointing to a multi-level (plussed) index entry worked  (visually, at least) without complaint. The output might look like:

Digby, John 73
Dilbert see Adams+Scott
Dirac, Paul 287

or

Digby, John 73
Dilbert see Adams, Scott
Dirac, Paul 287

where the second part is a literal repeat of what is in  the second argument of seeindex. (It is not, however, linked to the plussed entry as it would be to a single-level entry.)  However, current version (2018.07.27 19:12) generates a result like:

Digby, John 73
Dilbert
Dirac, Paul 287

along with the warning:

structure       > registers > invalid crosslink : Adams+Scott, ignored

Surely it is better to display the non-linked see entry as before (together with the warning message so that the non-linking is pointed out) and have a printable document than it is to display an empty entry!

--
Rik

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