When I run download nothing really happens (Zorro does not even try to connect to the broker, which it used to do). However, I cannot remember having changed anything important aside from the asset list.
Here is the script:

// Download Assets.dta and update price history of a certain asset (or all)

// comment this in and click [Trade] for updating Assets.dta
#define LOAD_ALL

function run()
{
// set date and click [Test] for downloading price history (not with MT4)
StartDate = 2009;
EndDate = 2013;
string name = "EUR/CHF";
#ifdef LOAD_ALL
while(name = loop("AUD/USD","AUD/JPY","EUR/CAD","EUR/JPY","EUR/GBP","EUR/USD","EUR/CHF","GBP/USD","GER30","NAS100",
"SPX500","UK100","UKOil","US30","USD/CAD","USD/CHF","USD/JPY",
"USOil","XAG/USD","XAU/USD","NZD/USD"))
#endif
{
if(is(TESTMODE)) loadHistory(name,1);
if(is(TRADEMODE)) asset(name);
}
}

Hi blaub4r,

Yeah, that caught me too. Zorro stores prices in files by year. For years older than the current year, if the file exists Zorro assumes that it's good and moves on. For the current year, Zorro will add new prices to an existing file, but it's unclear to me under exactly what conditions. Sometimes it did it for me, sometimes it didn't. It would make sense to me for it to add if the file modified date is older than EndDate or current time - BarPeriod, but I haven't spent the time to test that.

And, of course, Zorro only connects to the Broker when it needs to.

HTH.

I've just recently completed downloading all the data for all the pairs I'm interested in right now, including re-downloading years that were incomplete for whatever reason. Here are some tips I learned (using Zorro 1.12.1):

First, make sure Zorro is set to use an FXCM account, not MT4. I think I read somewhere that MT4 accounts do not provide adequate history.

Then, what I do is I go into the Zorro\History folder and move ALL files for the particular asset I'm working on into a temporary folder (for example, if I currently have 2008-2013 on AUDCHF but want some older years, I will do this so that Zorro cannot see any of AUDCHF)

Then just fire up the Download script and tell it to loadHistory on the pair(s) and year(s) you want. Due to the bug mentioned elsewhere in v1.12.1, it "sometimes" hiccups at the first attempt while subscribing the asset. But a second attempt will usually give you what you want.

After the new .bar files are downloaded, I re-integrate all the rest of the .bar files that were temporarily moved aside.

Hope this helps. Worked pretty reliably for me.

Thanks, the idea with the temporary folder worked, Zorro tried to connect to the broker (although I never had to do this before).
But Zorro did not manage to download the data, instead I got "Broker: Error - request failed" so there's perhaps some issue with the server?

It could be that the server is down on their end (I think I experienced this at one point myself as well).

One thing I would do to help verify this theory is to attempt to download a year and pair that you KNOW should be there for sure. For example, move all EUR/USD to the temporary folder and then attempt to download EUR/USD for 2012.

I do know it's very particular... you have to have Zorro set on FXCM, have valid login credentials entered (note: I only tried Real FXCM, not Demo)... and have the asset name exactly the way the broker expects (ie EUR/USD with the slash for FXCM)