Solr upgrade from 1.4 to 3.6

[Manepalli, Kalyan]

Hi all,
                We are trying to upgrade our solr instance from 1.4 to 3.6. We 
use SolrJ API to fetch the data from index. We see that SolrJ 3.6 version is 
not compatible with index generated with 1.4.
Is this known issue and is there a workaround for this.

Thanks,
Kalyan Manepalli