The creator software knows any updates from FlipBooks. Every time an output is generated which is considered as a new object FlipBook. Each FlipBook (and therefore each new version of a new FlipBooks) gets a unique Facebook ID (32 digit code of letters and numbers). Some contents of the FlipBooks are inextricably linked to the Facebook ID to prevent misuse of the data. Accordingly, it can cause problems when two versions of a FlipBooks be mixed with an update that is only overwriting of some files and not others.
We recommend that with every update to clear the contents of the previous FlipBook folder completely and then upload the new completely new FlipBook.