Steps to reproduce:

Notes:

1. These elements exist in the NVDA user interface and work fine and also seemly located in the correct positions (I only checked with "focusHighlight-5.3.nvda-addon") but they are visually invisible for Right-To-Left languages. But this causes serious difficulty for partial sighted users and developers that use NVDA for checking the accessibility of their designs.
2. The attached screenshots are only an example while the issue described completely in the below.
3. These elements that I found all are buttons & combo boxes that located in a grouping box and they are constantly visually invisible in all Right-To-Left languages that I checked: Arabic (ar), Persian (fa), and Hebrew (he)! So I use their English names for the explanation purpose in the below:

NVDA menu: Preferences submenu: Settings... NVDA: General (normal configuration) dialog:

• Categories: Speech: Synthesizer (grouping): "Change (button)" is invisible!
• Categories: Braille: Braille display (grouping): "Change (button)" is invisible!
• Categories: Document Formatting: Pages and spacing (grouping): "Line indentation reporting (Combo box): Off/Speech/Tones/Both Speech and Tones" is invisible!
• Categories: Document Formatting: Table information (grouping): "Cell borders (Combo box): Off/Styles/Both Colors and Styles" is invisible!

NVDA menu: Tools submenu: Create portable copy... Create Portable NVDA (dialog):

Portable directory (grouping): "Browse (button)" is invisible!

NVDA menu: Help submenu: Welcome dialog... Welcome to NVDA (dialog):

• Options (grouping): "Keyboard layout (combo box): desktop/laptop" is invisible!

NVDA menu: Configuration profiles... Configuration Profiles (dialog):

following buttons (all of them), in the unnamed grouping, are invisible!

• Manual activate (button)
• New (button)
• Rename (button)
• Delete (button)

Actual behavior:

NVDA read correctly and also interact correctly with these visually invisible elements but the elements are hidden for partially sighted peoples and sighted people that want use NVDA for check accessibility.

Expected behavior:

NVDA must draw these elements like any other ordinary elements in its user interface for all languages.

System configuration:

NVDA Installed/portable/running from source:

Both Installed and Portable

NVDA version:

nvda_2018.2.1

Windows version:

Windows 7 x64 Ultimate. Version: 6.1.7601 Service Pack 1 Build 7601

Name and version of other software in use when reproducing the issue:

None. just NVDA

Other information about your system:

I am a sighted user that test NVDA and my first local is Persian.

Other questions:

Does the issue still occur after restarting your PC?

Yes, this problem constantly occurs.

Have you tried any other versions of NVDA?

Yes. I tested even with NVDA 2017.4 that had a different user interface. In that old version, some things were ok such as buttons that change synthesizer (I think because in NVDA 2017.4 those buttons were not located in a grouping box)! But some of these issues were even there, for example in the Welcome to NVDA (dialog), in its Options (grouping), where the "Keyboard layout (combo box) with the values of desktop/laptop" was invisible!