Check and Upgrade Latest ZK Binary Distribution
From Documentation
Studio Bundled ZK Library
ZK Studio is bundled with the latest ZK library, for example ZK 3.6.1. After installing ZK Studio, you can see ZK library inside the project ZKs.
Manually download and configure
Downloading the ZK Library:
You can also use a downloaded ZK binary distribution to run or develop a ZK Web Application, please download the latest version from ZK Recommended Releases and save it to a location of your choosing. You can extract the content, but it is not necessary.
Import ZK library
Please refer to ZK Studio Feature ZKs