You have to upgrade to latest release (5.16), then upgrade the boot loader, then downgrade to 5.11, create a metarouter, then upgrade back to 5.16
Yeah, there was another thread somewhere about this...as I recall, it has something to do with the change in flash size between the 1100AH "mark I" and the 1100AH "mark II" (from 512MB to 64MB), as the problem only happens on the "mark II" model. It's like something gets confused about the available amount of free disk space or something. But I thought that although you had to downgrade and re-upgrade (which somehow triggers a change?), you didn't have to create the MRs while it was downgraded...I'm pretty sure that you could immediately re-upgrade after the downgrade and then create MRs to your heart's content while running the latest version. (I don't have any "mark II" routers at my disposal for testing, otherwise I'd experiment with this.)
EDIT: Found it: http://forum.mikrotik.com/viewtopic.php ... 99#p305199
; I was wrong: doesn't have to do with the NAND size. Apparently the problem is that in certain situations RouterOS on the 1100AH is accidentally configured to load the multi-CPU kernel meant for the 1100AHx2, and the latter device does not support MetaROUTER. So running that kernel disables MetaROUTER support even on devices that it is officially supported on. I guess downgrading to some older version and then upgrading back to the current release again somehow causes this to get fixed.
I wonder what would happen if you simply re-installed the latest version with NetInstall, instead of doing the downgrade/upgrade dance? Might be easier/faster if it works.