I dont think it realy is a bug, however its surely is too anyoing to be WAD:
In my current game im suffering from massive amounts of interrupts, most of them happen daily. This has been going on for at least 1 ingame year, probably more like close to 3 (in the beginning i thought it would pass by and didnt keep track).
What i think is causing this is a whole lot of swarm ships in the home system of the NPC race. Using Spacemaster + exporting the event files shows an awefull lot of stuff like this:
9th March 2042 19:29:46,Star Swarm,Halitherses,Hostile Ship Contact! Contact ID: Canberra 007, Class ID: Canberra, Race ID: Herzberg Aliens #202, TCS 154 Active Sensor S112/R74 (Existing)
11th March 2042 19:29:46,SM Only,System 0,Sub-pulse length adjusted due to potential fleet interception
27th March 2042 05:44:46,Orkney,Sol,A new ship of the Nollaig class from the Sao Paulo Aliens #204 has been detected in Sol. Our intelligence service has designated the new ship as the Nollaig 933.
27th March 2042 05:44:46,Orkney,Sol,New Thermal Contact! Contact ID: Nollaig 925 (New), Class ID: Nollaig, Race ID: Sao Paulo Aliens #204, Strength 160
Also stuff like this, however less common:
1st April 2042 19:29:46,Orkney,Sol,An alien ship in orbit of Sol-A Asteroid #111 is emitting significant radiation. Planetary Radiation Level is now 413
Sometimes in between actual fighting takes place, however 99% of the time this is not the case. Is it possible that the NPC race's homeworld is not attacked but the ships hover next to it? Is there anything i can do? I can upload the entire log (and savegame) if it is of any help.