Error - SEVERE: Unable to reconstruct submission and unable to export csv data

Hi @Karthik_Cs, please note that Aggregate is no longer being supported. Central is now the ODK server. The post below has for more details about the end-of-life for Aggregate.

However, someone on the forum may still be able to help you.

You might also try using Briefcase to extract the data: https://docs.getodk.org/briefcase-using/