Hybris Upgrade from 6.4 to 2105 Sync not working

[shijomjoseph]

Hi All,

Im getting below error while synchronization...Please help me and let me know how can i fix this?

Got error from worker SyncWorker<00006A3A 1 of 1> errorText is: Caught unexpected error Cannot invoke "de.hybris.platform.jalo.type.RelationType.isOneToMany()" because the return value of "de.hybris.platform.jalo.type.RelationDescriptor.getRelationType()" is null synchronizing <8796094365697->8796103639041 [] deadlock(false)>

java.lang.NullPointerException: Cannot invoke "de.hybris.platform.jalo.type.RelationType.isOneToMany()" because the return value of "de.hybris.platform.jalo.type.RelationDescriptor.getRelationType()" is null

at de.hybris.platform.catalog.jalo.synchronization.CatalogVersionSyncCopyContext.isPotentiallyNonCopyableOneToManyAttribute(CatalogVersionSyncCopyContext.java:293)