Reporting a Bug

A good bug report makes the issue faster to reproduce and fix.

Before reporting, check whether the issue also happens in a supplied ModernUI example.

Required information

Please include:

Bug report template

ModernUI version:
MT5 build:
Windows version:
Broker/terminal environment if relevant:
File or example:
Does it happen in a supplied example? Yes/No

What happened:

What I expected:

Exact compile error or Experts log:

Steps to reproduce:
1.
2.
3.

Minimal code snippet:

Screenshot attached? Yes/No

Minimal reproduction

A minimal reproduction is the smallest possible EA that shows the issue.

Start from the quick-start skeleton, then add only the control or handler that fails.

Good reproduction:

• one .mq5 file
• includes ModernUI.mqh
• has OnInit, OnTimer, OnChartEvent, and OnDeinit
• shows the bug without your full trading system
• does not require broker execution logic
• does not depend on private account data

Visual/layout bug

For visual issues, include:

• screenshot of the chart
• chart size if relevant
• Windows display scaling
• DPI mode if changed
• light/dark theme
• whether dense mode is enabled
• whether the issue appears after resize, scroll, hover, or click

Useful commands/methods:

g_ui.LogDpiDiagnostics();

Compile bug

For compile issues, include:

• exact error text from MetaEditor
• file path being compiled
• the include line
• whether BasicPanel.mq5 compiles
• your ModernUI install path

The most common install path should be:

MQL5/Include/ModernUI/ModernUI.mqh

Runtime bug

For runtime issues, include:

• Experts log output
• what you clicked or typed
• whether the panel appears
• whether controls respond
• whether OnTimer and OnChartEvent are forwarded
• whether Shutdown() is called in OnDeinit

Performance bug

For performance issues, include:

• whether it happens in the performance stress test
• whether performance stats were enabled
• PerfStatsSummary() output
• event queue drop count
• chart size
• number of rows/items involved
• whether custom CellText or BindRow does expensive work

Do not send only screenshots for code bugs

A screenshot is useful for visual issues, but compile/runtime code bugs need exact error text and a minimal code snippet.

Support boundary

Bug reports should be about ModernUI.

Support does not include:

• writing a full EA
• debugging unrelated trading strategy logic
• solving broker execution issues
• custom product development
• fixing modified third-party libraries

Related pages

• Troubleshooting
• Common compile errors
• Performance counters
• Native input hosts