Hi.

Error on load
21.005 Error ModManager.cpp:1625: Error while running setup for entity prototype "sp-1-solar-panel" (solar-panel): next_upgrade target (solar-panel-2) must have the same collision mask.
Probably solar productivity mod incompatible (not sure) https://mods.factorio.com/mod/solar-productivity

Neither of those entities are created or modified by my mod, so I'm guessing the issue is on Solar Productivity's side, but I'll take a look later.

The problem is i added your mod today and got this error. Disabled - no error. :)

Huh. I'll take a look.

I just installed both and didn't have any issues. "solar-panel-2" isn't from either mods, though. Do you have any other mods that affect solar panels? Or want to share your save with me?

It also looks like Solar Productivity is not compatible with Flat Solar, so you won't get the productivity bonus even if it loads. I made some changes to support this but it'll require some updates to Solar Productivity as well. I posted in their discussion about this.