REAPER 7 is now in pre-release. There are a lot of new changes. One of them is the update of LUA to version 5.4. This means that a new version of LKC TOOLS needs to be created. If you want to test the scripts in pre7 builds of REAPER, manually install these versions through ReaPack:
LKC Render Blocks v1.5.2beta: http://premium.lkc.tools
LKC Content Navigator v1.07beta: http://premium.lkc.tools
LKC Grim Sync v1.04beta: http://premium.lkc.tools
LKC Variator v0.3.7 - new repo link: https://bit.ly/LKC-Tools
These versions are backward compatible with REAPER 6. If you encounter any issues or bugs, please write to contact@lkctools.com