macOS: AqBanking crashes on "Create user"

[Paul Makepeace]

Pretty much as the subject says: Tools -> Online Banking Setup... ->
Forward -> Start AqBanking Wizard -> Create User -> hard exit.

Is this a known issue? Couldn't find any similar experiences online.
Something else I need to install/configure? Some place I can helpfully
drop a crash report?

Process:               Gnucash-bin [20290]
Path:                  /Applications/Gnucash.app/Contents/MacOS/Gnucash-bin
Identifier:            org.gnucash.Gnucash
Version:               2.6.16 (2.6.16)
Code Type:             X86 (Native)

Crashed Thread:        0  Dispatch queue: com.apple.main-thread

Exception Type:        EXC_CRASH (SIGABRT)
Exception Codes:       0x0000000000000000, 0x0000000000000000
Exception Note:        EXC_CORPSE_NOTIFY

Application Specific Information:
Assertion failed: (l), function GWEN_List1_GetCount, file list1.c, line 59.

Thanks! Paul

About GnuCash:
"The GnuCash personal finance manager. The GNU way to manage your money!
This copy was built from rev 509ce16+ on 2017-03-26."