Thanks for that response, jcl. I tried what you suggested and get the same error messages when using the Tradetest script on a demo account. I can't see anything that looks out of place in my Assets.dta file. Also, it updates when I connect to MT4 via the bridge.

Would you mind taking a look at my Assets.dta file? Here is the contents of the file (FYI my strategy trades XAU/USD, EUR/USD and USD/JPY):

Name Price Spread RollLong/Short PIP PIPCost Margin Lot
AUD/USD 0.93521 0.00015 5.9670 -7.6460 0.0001 0.10694 10.000 1000.0
EUR/CHF 1.21409 0.00015 -0.1310 -2.0960 0.0001 0.11912 14.460 1000.0
EUR/USD 1.35232 0.00010 0.0960 -0.1180 0.0001 0.10694 14.460 1000.0
GBP/USD 1.70986 0.00014 1.2510 1.5290 0.0001 0.10694 18.284 1000.0
GER30 9701.50 1.50000 0.0000 0.0000 0.0100 0.50000 140.290 1.0
NAS100 3876.25 4.0000 0.0000 0.0000 0.0100 0.25000 207.260 5.0
SPX500 1951.50 0.50000 0.0000 0.0000 0.0100 0.25000 208.680 10.0
UK100 6567.00 2.0000 -0.0756 0.0000 1.0000 0.11949 6.000 0.1
US30 16916.00 5.0000 0.0000 0.0000 0.1000 1.00000 180.890 1.0
USD/CAD 1.07572 0.00017 -3.2810 2.1480 0.0001 0.09942 10.694 1000.0
USD/CHF 0.89780 0.00012 -0.1310 -1.4410 0.0001 0.11913 10.694 1000.0
USD/JPY 101.404 0.01100 0.2850 -0.8120 0.0100 0.10548 10.694 1000.0
USOil 98.030 0.08000 0.0000 0.0000 0.0100 0.07182 14.000 10.0
XAG/USD 21.130 0.03000 -1.7200 0.1300 0.0100 0.53475 11.299 50.0
XAU/USD 1221.46 0.20000 -1.6100 0.2700 0.0100 0.01070 14.071 1.0