For those who want to keep using:
Open mod zip and modify:
File info.json
Replace factorio_version from "1.1" to "2.0", same with dependencies. should be like that:
{
"name": "Beacon2",
"version": "1.0.3",
"title": "Beacon 2",
"author": "Clippy",
"factorio_version": "2.0",
"dependencies": ["base >= 2.0"],
"description": "Add tier 2 beacon + research. Stack size configurable. Vanilla friendly."
}
File \prototypes\entity.lua,
scroll to the very end and add line
b2.module_slots = 4
wherever across b2 properies. Should be like that:
...
b2.fast_replaceable_group = "beacon"
b2.graphics_set = beacon_animations()
b2.module_slots = 4
data:extend({ b2 })
...