Entity error in clientlog every time an Xsotan fleet jumped in

[Morpheus2014]

Every time an Xsotan fleet jumped in, I got massive lag up several minutes, (Singleplayer game) and this is the log I found in the clientlog:

 

2018-07-29 20-05-17| <Server> Danger! A large fleet of alien ships appeared!

2018-07-29 20-05-17| Danger! A large fleet of alien ships appeared!

2018-07-29 20-05-18| Client Communicator received message that remote is not receiving UDP packets. Switching to TCP only.

2018-07-29 20-05-26| Entity with index f6008da0-48eb-4b82-821c-778ace1c9d7b has no script with index '0'.

2018-07-29 20-05-27| Entity with index 034cace4-f9e0-4161-bbe4-0b9b9a3a4300 has no script with index '0'.

2018-07-29 20-05-27| Entity with index 4a044ed5-b3cf-435a-a130-846bd2d936c0 has no script with index '0'.

 

Also sometimes the same error occurred when a pirate fleet jumped in:

 

2018-07-29 20-10-09| <Server> Pirates are attacking the sector!

2018-07-29 20-10-09| Pirates are attacking the sector!

2018-07-29 20-10-10| Entity with index 55b3bff0-c8f9-4835-a181-3d12d9d85317 has no script with index '0'.

2018-07-29 20-10-10| Entity with index ee89cd87-0321-48f6-b6bb-91d2421ddf18 has no script with index '0'.

2018-07-29 20-10-11| Entity with index 6d3ada9e-4471-4acc-bc5d-06095c83eed9 has no script with index '0'.

 

What is the cause of this "no script" error?

Haven't tried to reproduce it it yet in a fresh Galaxy.