Strange error in JOIN ON clause

The exception:
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Error: An ON clause associated with a JOIN operator is not valid.
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happens when I run the below SQL script:
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SELECT
THIS.DOSSIERTEMPLATE_ID
FROM DOSSIERTEMPLATE THIS,
ENTITLEMENT UNBOUND_ENTITLE
INNER JOIN
ENTITLEMENT II
ON UNBOUND_ENTITLE.ENTITLEMENT_ID = II.ENTITLEMENT_ID
INNER JOIN
DOSSIERTEMPLATERESOURCE BB
ON II.ENTITLED_TO_RESOURCE_ID_OID = BB.DOSSIERTEMPLATERESOURCE_ID
INNER JOIN
I18N THIS_LABEL
ON THIS.LABEL_I18N_ID_OID = THIS_LABEL.I18N_ID
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It works fine if I run without the LABEL join
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SELECT
THIS.DOSSIERTEMPLATE_ID
FROM DOSSIERTEMPLATE THIS,
ENTITLEMENT UNBOUND_ENTITLE
INNER JOIN
ENTITLEMENT II
ON UNBOUND_ENTITLE.ENTITLEMENT_ID = II.ENTITLEMENT_ID
INNER JOIN
DOSSIERTEMPLATERESOURCE BB
ON II.ENTITLED_TO_RESOURCE_ID_OID = BB.DOSSIERTEMPLATERESOURCE_ID
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The column LABEL_I18N_ID_OID is BIGINT and has a FK to I18N_ID, which is BIGINT as well