This bug only affect migrated instances. In 2.9 Oracle migration script the column RECIPIENTS_AS_TEXT_BCC was defined as VARCHAR2(4000), but in Sakai 10 is mapped as materialized_clob in hibernate and throws this error:
error code ; Invalid column type: getCLOB not implemented for class oracle.jdbc.driver.T4CVarcharAccessor
The solution is change the column type running this script:
alter table mfr_message_t add (RECIPIENTS_AS_TEXT_BCC_B CLOB);
update mfr_message_t set RECIPIENTS_AS_TEXT_BCC_B=RECIPIENTS_AS_TEXT_BCC, RECIPIENTS_AS_TEXT_BCC=null;
alter table mfr_message_t drop column RECIPIENTS_AS_TEXT_BCC;
alter table mfr_message_t rename column RECIPIENTS_AS_TEXT_BCC_B to RECIPIENTS_AS_TEXT_BCC;
This should be included in Sakai 10 Oracle scripts.