Failing to upload the form to Aggregate

1. What is the problem? Be very detailed.
I have designed a form for microcensus/ We will list all buildings in a cluster; And if there are many households in a building , we will list all buildings then if there all household members in a building will be listed.

To do that

I have started with a first begin repeat group: to list all household

then in the household: I also use begin repeat to list all household members.

But When I try upload the form in to server: I am getting this message

2. What app or server are you using and on what device and operating system? Include version numbers.

I am using ODK and ODK server ( appspot.com)
3. What you have you tried to fix the problem?
I tried without solving the problem
4. What steps can we take to reproduce the problem?
uploading the xml to the server
5. Anything else we should know or have? If you have a test form or screenshots or logs, attach below.
ODk can allow to use begin repeat under an other begin repeat.: I use begin repeat twice.

Hi @pakilimali
We're glad you're here. When you get a chance, please introduce yourself on this forum thread. I'd also encourage you to add a real picture as your avatar because it helps build community!

Could you attach that form here (xls version ideally)?
What version of ODK Aggregate are you using?

BTW. Have you heard of ODK Central? It's our new server which we recommend using because ODK Aggregate is no longer actively maintained.