As posted here #102 (comment)

Fixed this issue however there is a fix you can do too in the mean time.

Firstly if you can still load the world, load it then remove all power to Sync shells and re-apply power. Basically this should make the mod remove them as chunk loaders and re-add them but this time do the check (I assume you had the shells placed down before the update)

If you can't open the world, open the world save location and using NBTExplorer open forcedchunks.dat and delete the entries for Sync. It means you'll need to revisit all your shells again (just load the chunk they are in) but should fix this issue until it gets pushed to a version. You may need to cycle power to them too to have them re-register as a shell but it should work.

Thanks!