On 29.01.2015, at 20:10, Jerry Bell <jdbellomm@gmail.com> wrote:Hello,I'm trying to run the JSBridge callback example from a 4.5 image. JSBridge.st is loaded and I'm running under Chrome on Windows. I get an error: "Error:primReturnFromCallback: failed. " Digging a little in the debugger, I find in JSObjectProxy>>handleCallback, result is : "Error: Error: This block accepts 2 arguments, but was called with 0 arguments".Modifying the example with a callback block with 0 arguments works.Hi Jerry,you found a bug :)Apparently I’ve never tested this with block closures, only with block contexts.I created an issue: https://github.com/bertfreudenberg/SqueakJS/issues/29But I think it’s going to be trivial to fix. We just have to handle both blocks and closures in js_primitiveGetActiveCallbackArgs():- Bert -