Are you getting mad searching, digging all websites and forums what this error means? Thinking how you can solve the problem? Well now youre in the right direction I will share you how did I solve the problem, I got to the point that I need to share my solutions and trick how did I solve this ePub error, to solve this problem is simple just follow the step by step process.
Zipped the mimetype file first, means only mimetype file in a zipd may look similar in the picture below.
Drag and drop the remaining folder to the zipped/mimetype.zip, so now our zipped file contain the entire necessary file and folder for our ePub, may look similar in the picture below.
Now just rename the zipped file to .epub extensions, mine I just rename it to myeBook.epub see the image below for a sample.
That’s it hope it helps :), enjoy creating your ePub eBook.