I updated all my history files via FXCM and tried starting Z7 and Z12 using the IG plugin. Deliberately on Sunday to be sure I am not missing any latest price data. I did also check the _2017.t6 files for completeness using ZHistoryEditor. As expected, data is included up to last Friday night and no gaps except the week-ends.

Z7 started without errors with the following Zorro messages:

Z7 .x ..
ig.dll => IG plugin mounted
Z7.55: PH PR M 100 H 5 W 2 V 2 .
Login IG.. at UTC 07-16 13:16.
Load EUR/USD prices.. 680+33 h, gap 41 h
Load USD/JPY prices.. 680+33 h, gap 41 h
Load GBP/USD prices.. 680+33 h, gap 41 h

Trade: Z7 2017-07-16
Lookback period (480 bars) .
Read Z7.c

I understand "gap 41h" is due to the weekend gap, so no issue. However, I don't understand where the +33h is coming from? 3 x 33h x 60 min/h = 5940 historical bars consumed ... :-(

Hoping IG will reset the quota at the beginning of the calendar week I tried starting Z12, too:

Z12
Login IG... at UTC 07-16 13:17
Z12.54: PH PR M 100 H 5 W 2 V 2
Load EUR/USD prices.. 2800+211 h, gap 41 h
Load USD/CHF prices.. 2800+211 h, gap 41 h
!Severe error occured, check igzplugin.log logfile!
!Severe error occured, check igzplugin.log logfile!
Error 053: CX.D.GBPUSD.CASH.IP unavailable at this time
!Severe error occured, check igzplugin.log logfile!

[...]

!Severe error occured, check igzplugin.log logfile!
Error 053: CX.D.XAGUSD.CASH.IP unavailable at this time
V 1.600 on Sun 17-07-16 15:17:06 (Zorro S subscription)

Trade: Z12 2017-07-16
Read Z12.fac
Read Z12.par
Lookback period (500 bars)
[184: Thu 17-03-16 16:09] 1.0722/1.07441.0713/1.0736
Error 033: GBP/USD missing in INITRUN
Error 011: Function ATR called with invalid parameters (no price)
Error 011: Function BBANDS called with invalid parameters (no price).
[185: Thu 17-03-16 20:09] 1.0736/1.07711.0708/1.0768

Of course, the igzplugin log shows:
ERROR c.danlind.igz.adapter.RestApiAdapter - Exception when getting historic prices for epic CX.D.GBPUSD.CASH.IP, error was {"errorCode":"error.public-api.exceeded-api-key-allowance"

Again, I wonder where the +211h is coming from? The data files were up-to-date ...

Obviously PRELOAD was set and recognized. So what else was wrong?
Any help much appreciated. Many thanks in advance!