lb5-347 Win 10. AND on floats errors (Unhandled exception)

[tsh73]

x=1.5
y=2
if x and y then print "t" else print "f"
errors with Exit Proceed Continue buttons.
(btw is Proceed and Continue differ? For me program stops anyway. But on Exit LB closes)

==2019/3/1==0:59:07==BEGIN RUNTIME DIAGNOSTIC DUMP
Note: this file stored in VisualWorks #source (UTF-8) encoding

Cause of Dump: Unhandled exception: Message not understood: #bitAnd:
Smalltalk Version: 'VisualWorks®, Pre-Release 8.3.2 (apr18.3) of 20 апреля 2018 г.'
Object Memory versionId: #[172 47 76 176 83 2 3 4 172 47 76 176]
Class creating this dump: ErrorDumper
------------------------------------------------------------
Active Process
Process named: 'Unnamed Process'
Process priority: 50
Process identity hash: 9237
Context Stack:
[1] optimized [] in Director>>direct:
[2] BlockClosure>>cull:
[3] MessageNotUnderstood(GenericException)>>performHandler:
[4] MessageNotUnderstood(GenericException)>>propagatePrivateFrom:
[5] MessageNotUnderstood(GenericException)>>propagateFrom:
[6] MessageNotUnderstood(GenericException)>>propagate
[7] MessageNotUnderstood(GenericException)>>raiseSignal
[8] Double(Object)>>doesNotUnderstand:
[9] optimized [] in UndefinedObject>>unboundMethod
[10] IfThenClip>>animate:
[11] optimized [] in [] in Director>>direct:
[12] OrderedCollection>>do:
[13] optimized [] in Director>>direct:
[14] BlockClosure>>on:do:
[15] ProgramDirector(Director)>>direct:
[16] ProgramDirector>>direct:
[17] ProgramDirector(Director)>>for:direct:
[18] ProgramDirector>>for:direct:
[19] Program>>runWithDirector:
[20] optimized [] in Program>>runForked
[21] BlockClosure>>on:do:
[22] optimized [] in Process class>>forBlock:priority:

------------------------------------------------------------
Unhandled Exception:
class: UnhandledException
creator: UnhandledException
errorString: Unhandled exception: Message not understood: #bitAnd:
parameter: a MessageNotUnderstood

==2019/3/1==0:59:07==END RUNTIME DIAGNOSTIC DUMP