I have a BGP session with a C class that needs to be broken down into a /25 and two /26 as a static route to 3 other routers (the BGP router simply distributes)
Now if I establish the BGP with a single /24 static route to one router all works great
So I assumed if I turn aggregation on I could do this so I setup an aggregation on that C class.

I then setup 3 static routes on the smaller sections the aggregation screen shows 3 sections aggregated.
However the advertizing screen shows incomplete and the IP route screen shows DbaU on the C class (the unreachable U obviously the problem)
I have tried every combination of the 3 tick options (summary only, inherit attributes and include IGP)

Can anyone give me the dummies guide to what I am doing wrong with the aggregation.

I have a BGP session with a C class that needs to be broken down into a /25 and two /26 as a static route to 3 other routers (the BGP router simply distributes)
Now if I establish the BGP with a single /24 static route to one router all works great

Up to this point, everything was good..

Go back to this point in your configuration..

Then IP - Route, Add

Use this to route the subnets to the other routers.

192.0.2.0/25
172.16.0.2 (whatever IP the other router has)

192.0.2.128/26
172.16.0.6

192.0.2.192/26
172.16.0.10

Resolved problem with help of a local Mikrotik expert

Issue was I had the "redistribute static" box ticked
Which when you put in a static route to a subnet range like /25 /26 /27 etc (suggested by kevinds above and I was doing) sends it out to the upstream and breaks the BGP because it can't match the /24 prefix there on the upstream provider.

In my head the advertizing went (seemed logical)
BGP system ===> Aggregator ====> Filter Out

I thought I was sending the subnets to the aggregator but I was actually sending them out upstream.
The aggregator must already look at the route table and sniffs out the subnets because you don't need to tell it about the static routes.