Missed Upload R11

Not usually, no. You can try to contact the service desk but it seems unlikely that they'd be willing to make allowances given it was not as a result of a technical issue. As long as you get your R12 submission in though, I can't see it representing an enormous issue for you? Granted, any changes you've made (and funds you were potentially expecting) will be delayed by a month.. but in the grand scheme of things you will still get what you're owed. 

08000 150 600 is the published helpline. You may have more luck raising a ticket via the portal though, as you can specifically refer to the issue as being ILR submission related, rather than going round the houses. I did have a number directly for the ILR team but I can't for the life of me find it.  

I have raised a ticket, thank you. 

We already try to get an ILR banked at least 2 days before the deadline in case we or the SLD website have any issues.

Hi this happened many years ago to us, they take your previous return to estimate your payments for the month you are missed, no completion payments though or any new starts for that month, it was a lesson learned and caused many sleepless nights, now we upload every week to make sure. At least you will get paid though, it reconciles correctly on the next batch.