The connection was refused by the peer....

mount : ioptron zeq25 ( connected by indi)
Camera : QHY8L ( connected by indi)
Guide camera : QHY5L2-M ( connected by Lin_guider, not Indi)

Unfortunately, I have never played with Lin_guider using its remote access method. But, I would suggest you load Lin_guider, its cccd firmware for the cameras, and run the program independently of KStars, first. If it works ok, then, the problem is with KStars.

If not, you most likely have firewall, UDP setting, permissions, or port assignment issue. I have used KStars and Lin_guider separately with no problems. I would suggest separate desktops for each works very conveniently. If one of the software then crashes, its very easy to recover. i.e. KStars crash while guiding. One can simply restart KStars, connect and sync.

Best wishes,
Dan

also take a look in this thread:
www.indilib.org/forum/ekos/2219-items-fr....html?start=48#20124

· Set the Lin_guider port of Ekos setting to 5656
(If you can not connect, try 5001)
· CCD of Ekos setting is QHY → Simulator