When you run "Buy now" or "Sell now", the result is a new trade. These blocks are under "on Tick" = it's possible to run then on every tick! Because of that, some filter is added for them, like a "No trade is running" block. Now, it really matters what are the settings in this block and "Buy now/Sell now" - those settings must match!
Again, in your project you are asking "There is no EURUSD trade?". If you are working in GBPUSD the answer will be always Yes (backtest), so the block will always pass. It's like it does not exists at all.
I tried this in EURUSD, this is the result: http://prntscr.com/70uuum So, in EURUSD there is no problem at all. Again, because "No trade... " is set up for EURUSD only.