"HIVE_CURSOR_ERROR: java.io.IOException: Start of Object expected" error when using Hive JSON SerDe

I recently switched from using the "org.openx.data.jsonserde.JsonSerDe" to "org.apache.hive.hcatalog.data.JsonSerDe" so I can use custom timestamp formats ( as described here in the AWS Docs ). But now I get a "HIVE_CURSOR_ERROR: java.io.IOException: Start of Object expected" error from Athena.

I changed it for 6 tables (all containing timestamps) and only 2 are failing now. I don't see any difference between the tables.

I had some files that where 0 Bytes long and deleted them from S3 but I am still getting the error.