Publication looks corrupted.

[yashbhardwaj786]

Hey Team, Greetings for the day. I am implementing your sdk and I tried test app, When I am trying to fetch epub file from the server I am facing the below error.
UserError: Publication looks corrupted.
ReadError.Decoding: An error occurred while attempting to decode the content.
IOException: Error on ZipFile unknown archive
org.readium.r2.shared.util.zip.compress.archivers.zip.ZipFile.(ZipFile.java:533)
org.readium.r2.shared.util.zip.compress.archivers.zip.ZipFile.(ZipFile.java:459)
ZipException: Archive is not a ZIP archive
org.readium.r2.shared.util.zip.compress.archivers.zip.ZipFile.positionAtEndOfCentralDirectoryRecord(ZipFile.java:1074)
org.readium.r2.shared.util.zip.compress.archivers.zip.ZipFile.positionAtCentralDirectory(ZipFile.java:941)

The URL which one I am using is not corrupted, we can easily download the epub file from the given url.
Kindly guide me what the fixes here can we implement.