The mod More Enemies (0.7.0) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event more-enemies::on_tick (ID 0)
Unknown entity name:
stack traceback:
[C]: in function 'find_entities_filtered'
more-enemies/scripts/service/attack-group-service.lua:386: in function 'get_target_entity'
more-enemies/scripts/service/attack-group-service.lua:110: in function 'do_attack_group'
more-enemies/scripts/controller/spawn-controller.lua:133: in function <more-enemies/scripts/controller/spawn-controller.lua:49>

Can confirm this error. It happened to me after 1 hour play under 0.7.0 update.

I play with Frost, Toxic, Explosive and Proto biters with vanilla biters in the mix.

Hello! Thank you both for the report. Apologies for the issue and oversight on my part. I've been able to recreate the issue locally, and I believe I know what the issue is. Hoping to have a fix out relatively soon

I've fixed the issue locally, and attack groups are now spawning without error. Update should be out soon.

This should be fixed with version 0.7.1 - apologies for the issue and thanks again for the report!

Please let me know if you encounter any other issues.