Where can I find the log file on the disk?

Metatrader saves log files to disk in the Data Folder the following catalogues:

    1. for MT4
      • log Strategies in the \NMQL4Logs directory.
      • log Log in the Logs directory.
      • log The strategy tester log in the folder `Tester Logs' (for Trading Simulator - Strategy Tester)
    2. for MT5
      • log Experts in the directory \NMQL5.
      • log Log in the Logs directory.

Each day a new log file is created - the file name indicates which day it is from e.g. 20200902.log. IMPORTANT - to copy a log file you must first close Metatrader which will save all the information to disk. It is advisable to open the Data Folder before closing to easily find the file.