I have routerOS 2.9.43 x86 platform.
upstream BGP session is conected. But my prefixes not anounce to upstream.
Router configuration is cloned from routerOS 2.9.29 where all is worked!
Where is problem?

i dunno, post your /routing export so we can have a look. it could be a million things and I dont want to guess them all.

/ routing filter
add chain="DINET IN WORLD" invert-match=no action=passthrough \
set-nexthop=89.208.23.29 comment="" disabled=no
add chain="DINET OUT WORLD" prefix=89.208.120.0/23 invert-match=no \
action=passthrough comment="" disabled=no
add chain="def out" invert-match=yes action=discard comment="" disabled=no
/ routing bgp instance
set default name="default" as=42569 router-id=0.0.0.0 \
redistribute-connected=no redistribute-static=no redistribute-rip=no \
redistribute-ospf=no redistribute-other-bgp=no out-filter="def out" \
client-to-client-reflection=yes ignore-as-path-len=yes comment="" \
disabled=no
/ routing bgp network
add network=89.208.120.0/23 disabled=no
/ routing bgp peer
add name="dinet" instance=default remote-address=213.248.0.1 remote-as=12695 \
tcp-md5-key="" nexthop-choice=default multihop=yes route-reflect=no \
hold-time=2m40s ttl=2 in-filter="DINET IN WORLD" out-filter="DINET OUT \
WORLD" comment="" disabled=no

it's my bgp configuration
89.208.23.29 - it is my ISP gw

remove the out-filter="def out" on the bgp instance, and use it on the peer only.

I've also had weird quirks with the invert-match option. Your 'def-out' filter doesn't really need to be there I don't think.

Better to use it like the firewall and put a discard/reject at the end of the chain. Accept what you want, and then reject at the end. Also, use action=accept instead of passthru.

the 'network' command was new and I never tested it. I always stick the subnet in the routing table on a loopback interface, that way I can see it with the rest of them.

Yea it's work!
But i have any problem, i have 2 BGP instanses and piriodicly my routing table and all other (Firewall rules) is cleared forwarding do not work, bgp sessions is no longer connected.

/routing bgp peer print - show me at this time clear list
when i'm reboot the system - all is good and work.

That's the routing crashing : ) I haven't had good luck with 2.9.43 BGP routing-test yet. I am still using .26 since it's been stable for us. Afraid to upgrade production routers that are working. There were quite a few versions we tested that just worked horribly and would spin out of control like your above screenshot.

What version of MT is stable?
How I'm can to downgrade a RouterOS? Only reinstall all system? old config is works propertly, or config all newly!?