Type about:preferences#content<enter> in the address bar. Across from fonts and colors, press the Advanced button. On the bottom, turn on Allow Web Sites To Choose Their Own.

You can check for corrupted and duplicate fonts and other font issues: http://www.thexlab.com/faqs/multipleappsquit.html - Font Book 2.0 Help: Checking for damaged fonts http://www.creativetechs.com/iq/garbled_fonts_troubleshooting_guide.html

This thing is already checked. Other browsers are showing bengali font correctly. Do I still need to checkf ro duplicate and corrupted fonts from the sites given above?

Do you see any text or do you only see little boxes with the hex code?

You can right-click in the space where text should be and select "Inspect Element" to open the Inspector (Firefox/Tools > Web Developer) with this element selected. You can check the font used for selected text in the Font tab in the right pane of the Inspector.

• https://developer.mozilla.org/Tools/Page_Inspector
• https://developer.mozilla.org/Tools/Page_Inspector/How_to/Examine_and_edit_CSS

To be specific my problem is with the compound characters. Firefox is showing compound characters breaking up into each component and so the whole thing becomes unreadable.

What font is Firefox using for the Bengali glyphs (see my above reply)?

It is possible that this font isn't working properly. You could try a different default font.

You can try different default fonts and temporarily disable website fonts to test the selected default font.

• Tools > Options > Content : Fonts & Colors > Advanced
• [ ] "Allow pages to choose their own fonts, instead of my selections above"

The Bengai font name is Nirmala. I changed my default font to Adarshalipi but no change. Now I also do a thing: My region was US, I changed it to Bangladesh, but I didn't restarted my machine aftr that change. I did it 'cos my local language might be misunderstood.

You can try to disable hardware acceleration in Firefox.

• Tools > Options > Advanced > General > Browsing: "Use hardware acceleration when available"

You need to close and restart Firefox after toggling this setting.

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

You can check if there is an update for your graphics display driver and check for hardware acceleration related issues.

• https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration

Yeeeeeeeeeeeeeeey. Problem solved. 'Use hardware acceleration' was the culprit. Thank u very much indeed.