No enemies at mission points

Greetings, Adoxa! Can you help me again?
The problem: it happens rarely on my server and i have been observing this problem for a very long time. The reasons of this problem are still unknown for me: when the players had reached the key point at that point npc didn’t appear and players can’t to cancel the mission. The only resolution of this - restarting the server. Maybe you have the another resolution?
Probably, it connected with npc’s zones? But I can’t find what is wrong. And also i checked zones and ranks of npc but also didn’t find any problems.

I am also have my old post about it: https://the-starport.net/freelancer/forum/viewtopic.php?post_id=58357#forumpost58357
The problem appeared very often and i solved it. But not finally.

khayman wrote:
Hi, just thought… have you edited ny of these?

2500f	content.dll	11C2C4	Vital	distance at which NPC mission target ships in randommissions are created
2625f	content.dll	0F17D9	Vital	distance at which NPC wave ships in randommissions are created
7500f	content.dll	11C2B0	Vital	distance at which mission target solars in randommissions are created
6000f	content.dll	11CBCC	Vital	distance from 1st mission waypoint that second waypoint (and ships at it) in randommissions are created
3500f	content.dll	11C2C8	Vital	core retreat distance from randommission waypoint, modified by below offset

Yes, my content.dll looks like this

3000f	content.dll	11C2C4	Vital	distance at which NPC mission target ships in randommissions are created
3125f	content.dll	0F17D9	Vital	distance at which NPC wave ships in randommissions are created
3000f	content.dll	11C2B0	Vital	distance at which mission target solars in randommissions are created
6000f	content.dll	11CBCC	Vital	distance from 1st mission waypoint that second waypoint (and ships at it) in randommissions are created
6000f	content.dll	11C2C8	Vital	core retreat distance from randommission waypoint, modified by below offset