Unsupported Construct Error


Can you help me on this issue that showing an error and preventing form deploying the form. The error message as below. I can not figure out where the problem is and what is causing the issue.

" unable to deploy
your form cannot be deployed because it contains errors:

ODK Validate Errors: >> Something broke the parser. See above for a hint. org.javarosa.xpath.XPathUnsupportedException: XPath evaluation: unsupported construct [filter expression] Result: Invalid "

Need urgent help.

I have found a solution for the problem. Thanks

Great to know that you found the solution for your issue. Also please be informed that you could always test your xlsform on this online validation site. It should help you identify the syntax error that is within the xlsform.

Thanks bro. Also I got a question. I am working for renowned humanitarian organization planning to collect about 70,000 data with KoBo with more than 250 variables. Is that gonna be a problem?

Please let me know.


Hello @Tamim,
Would you mind to share the solution / problem detail you found with the community?

If you are going with Collect, you might better use ODK Collect (the base of KoBo).


It was basically a logical error. I wanted to substract a non input variable and which does not comply. Also there were some issues where i placed faulty logic throguh relevant column.

Hey wroos why you suggesting to use odk? any particular reason? or am i gonna face any problem with KoBo?

Have a great day

Hi @Tamim,

Kindly please be informed that the KoBoToolbox account for the OCHA server is able to support unlimited data. But, also please be informed that you may have to demonstrate that your project is related with a humanitarian cause if and when you are asked to by a KoBoToolbox representatives. Thus, a case of 70,000 submission should not be a storage issue with KoBoToolbox (OCHA server).

Also please be informed that if your survey project is not that complex it should be able to handle a total of 250 variables.


Thanks very much for the valuable information. Can you please share any more information regarding when any KoBoToolbox representative may ask me about project related question? I mean at the middle of data collection, end or when it would be done?

Also Is it okay with you to give a check at my variables? It would be helpful for me. But please be advised that I have to share it in private as this is a project document and not open to all.

Normally, a KoBoToolbox representatives may not reach you out but if your project is affecting the server’s load balance you may be reached. Generally huge data collection from a single user may affect the server’s performance.

Regarding your second query on the total number of variables, you may have issues while loading your survey project with a lot of variables. Thus at this point you should understand that your survey project may have a large number of variables in it. Maybe this post discussed previously should help you understand what happens if you have too many variables for a survey project:

Do you suggest opening different account from different project member would solve or negotiate the issue? Then, we will with five different accounts for five different districts. Does it sound good? or does it comply with any terms of KoBo?

Thanks for sharing the post. I see the problem. I have in total around 450 variable with the calculation field. From enumerators side, it is within 250 variable or may be less.

It depends on how you wish to manage your survey project. Yeah having multiple account for a single project would also help us maintain the load balance of our servers.

Thanks for the suggestion. I was concerned about rules and regulation. I will definitely go with multiple account from multiple members. Also just want to inform the data will be collected with KoBo Collect mainly over 14 days. Just want to know, If there will be any server maintenance during January 3-20th.

Thanks for helping me out again. Much appreciated.

@Tamim, there is no schedule for server maintenance for the said date. Best Wishes!

You might get a reason here

Thanks. for the information.


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What was the solution??

Welcome back to the community @arnold_njogu! Would you mind describing your issue in detail so that the community could help you solve your issue.


You need to check carefully on the calculation or relevant column. The error raised for me as I referenced the same column name on which I used a relevant formula.

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