oracle apex strange zero division problem

I have simple report (not interactive). When I try to开发者_Go百科 remove column from its backing sql query it throws an exception

ORA-01476: divisor is equal to zero

UPD: exception is thrown after I try to remove a.page_name and save report

select a.page_name,a.page_id, b.report_name
from APEX_WORKSPACE_ACTIVITY_LOG a, reports b, APEX_APPLICATION_PAGE_IR c
where 
c.interactive_report_id = b.interactive_report_id
and c.page_id = a.page_id
and a.apex_user = :APP_USER --NVL(v('APP_USER'), USER)
and a.application_id = '157'

I suspect the column you are removing is being used somewhere. Try exporting the application and grepping the file for page_name

On the face of it that sounds like a bug in your version of Apex. If possible, recreate the problem in a public page on apex.oracle.com and then raise the issue on the Oracle Apex forum with a link to the example. The Apex development team participate in the forum and may be able to help.