Ever since version 5.00 build 5172, 24 Jul 2025 the compiler doesn't work anymore
- Terminal build number
- Writing and reading global variables
- Simple statements (expressions)
By the way - this issue with beta build was already reported:
MetaTrader 5 Platform update build 5120: Improvements and fixes
Alexander Voronkov, 2025.07.24 07:25
MetaTrader 5 build 5172
fatal compiler error: unknown error 0 0
More -
Forum on trading, automated trading systems and testing of trading strategies
New MetaTrader 5 platform version build 5120: improvements and fixes
Alexander Voronkov , 2025.07.24 08:13
MetaTrader 5 build 5173
fatal compiler error: unknown error 0 0
The problem remains.
---------------
So, the users are reporting it to official thread.
It was fixed:
Forum on trading, automated trading systems and testing of trading strategies
New MetaTrader 5 platform version build 5120: improvements and fixes
Alexander Voronkov , 2025.07.24 11:31
MetaTrader 5 build 5174
Solved! Thank you!
How exactly do you change your MetaTrader to stable? For me the updates happened automatically, out of my control
Download MT5 from your broker's website ... why? Because the brokers are updating MT5 to the stable build only.
Or - do not connect to MetaQuotes-Demo server in your MT5 (because MetaQuotes-Demo server is related to the beta testers and to update to the beta builds of MT5).
Download MT5 from your broker's website ... why? Because the brokers are updating MT5 to the stable build only.
Or - do not connect to MetaQuotes-Demo server in your MT5 (because MetaQuotes-Demo server is related to the beta testers and to update to the beta builds of MT5).

