If you don’t read our e-books then it may solve by these following solutions:
Font Problem: Download this bangla font from this link (download) . Then copy and paste into your Font folder.
PDF Reader software problem: Download software from these links like Foxit Reader, Adobe Acrobat Reader or any other updated PDF reader software as you like. Then install it in your computer/Laptop.
Browser problem: Update your Browser with latest version.
Operating system problem: It is better to update your operating system with windows 7 or above version.