CensusConnect relies on the Census API provided by the US Census Bureau. Although this API is stable, on rare occasions, they have server problems and cannot field the requests. Unfortunately, there is not much we can do at CensusConnect. They are usually able to resolve the issues within a few hours. CensusConnect will automatically begin functioning properly as soon as the Census API issues are resolved.
Certain columns (namely Sex Offender and % Tax Assessment) take longer time to load since they need to gather the data from several sources. To speed up the load time, limit your column selections to only census attributes.