I'm running the Z12 strategy on a demo account, using Zorro 1.88.2 and haven't got any problems.
While testing the plugin with the latest version of Zorro (1.88.6) I'm getting the same crash.
But after several tests it comes out that the error is not in the plugin but in the Z12 strategy, because Z1, Z2 and Z7 strategies work without any problems:

Zorro 1.88.6 in Diagnostics mode - Strategy Z12 with Verbose 15 and EUR/USD only
Plugin Result Diagnostics
FXCM ACCESS VIOLATION no errors
Oanda ACCESS VIOLATION no errors
Dukascopy ACCESS VIOLATION Error 055: No bars generated
vDukascopy-1.1 ACCESS VIOLATION no errors

Zorro 1.88.2 in Diagnostics mode - Strategy Z12 with Verbose 15 and EUR/USD only
Plugin Result Diagnostics
FXCM OK no errors
Oanda OK no errors
Dukascopy LOGOUT Error 055: No bars generated
vDukascopy-1.1 OK no errors