When trying to use the Default Texture that comes with the Continuity mod instead of making the connected textures all blocks just turn completely invisible.
What might be causing this? How can it be fixed?

Please provide your log file located in .minecraft/logs, filename is "latest"

latest.log

Update Indium, Sodium and Iris

Make sure to not forget to update any other mods that depends on them if you have any

Thank you, that fixed the issue.