Quote Originally Posted by su35 View Post
Is the 4.0.26 compatible with ZC 1.5.1? or it is for 1.5.3 only?
There has been no compatibility change in the software. While it is in the best interest of a store owner to upgrade to the most recent/stable version for many reasons, the software is written to continue support for all versions that it has previously been written, which I believe at this time is considered 1.3.9 through 1.5.3 with exception that 1.5.2 was not factored into the compatibility as it was not a formal release and really should not be used in a production environment anyways.

So, short answer, yes it is compatible with 1.5.1 also.