Hi,
try to turn on the debug:
# diagnose debug application reportd -1
# diagnose debug enable
and then try to create an run a report, the debug output should be something like this:
reportd_main.c[765] __handle_cron_message-Cron message. type=2, vd=MGMT
report_engine.c[50] rptengine_create_report_dir- Report directory: /var/log/MGMT/report/generated/On-Demand-default-2015-12-03-175614 is created successfully
report_engine.c[1188] rptengine_init_toc_list-
report_engine.c[1001] rptengine_handle_body-start body item
report_engine.c[907] _handle_image_item-Process image item: id=101, chart=fortigate_log.png
report_engine.c[403] _handle_text_item-Process text item: id=103, contents=FortiGate ${schedule_type} Security Report
report_engine.c[403] _handle_text_item-Process text item: id=105, contents=Report Date: ${started_time}
report_engine.c[403] _handle_text_item-Process text item: id=107, contents=Data Range: ${report_data_range} (${hostname})
report_engine.c[403] _handle_text_item-Process text item: id=109, contents=${vdom}
report_engine.c[907] _handle_image_item-Process image item: id=111, chart=fortinet_logo_small.png
report_engine.c[920] _handle_misc_item-Process misc item: id=121
report_engine.c[403] _handle_text_item-Process text item: id=301, contents=Bandwidth and Applications
report_engine.c[855] _handle_chart_item-Process chart item: id=311, chart=traffic.bandwidth.history_c
report_engine.c[855] _handle_chart_item-Process chart item: id=321, chart=traffic.sessions.history_c
report_engine.c[855] _handle_chart_item-Process chart item: id=331, chart=traffic.statistics
report_engine.c[855] _handle_chart_item-Process chart item: id=411, chart=traffic.bandwidth.apps_c
report_engine.c[855] _handle_chart_item-Process chart item: id=421, chart=traffic.bandwidth.cats_c
report_engine.c[855] _handle_chart_item-Process chart item: id=511, chart=traffic.bandwidth.users_c
report_engine.c[855] _handle_chart_item-Process chart item: id=521, chart=traffic.users.history.hour_c
report_engine.c[855] _handle_chart_item-Process chart item: id=611, chart=traffic.bandwidth.destinations_tab
...
report_engine.c[1024] rptengine_handle_body-
end body item
report_pdf_writer.c[711] rptwriter_pdf_end_report- PDF file is written to /var/log/MGMT/report/generated/On-Demand-default-2015-12-03-175614/default.pdf successfully
