Urgent - Related to Sigil-0.9.18

Hi All, I just downloaded Sigil-0.9.18 however I cannot use it the way I am comfortably using version Sigil-0.9.10. For instance, I cannot open an already created EPub file into reading mode, when I click on File followed by clicinkg on the name of the EPub, it opens in the window in a "Developer Mode" but not regular mode, similarly if I want to copy paste any words or sentences from MS Word to the Sigil window, I am not able to do it. Where as in version 0.9.10 I am comfortably able to do all this. Please help me on this
:help::help::help::help: