How reproduce issue: Upload file and then delete it. Upload same file again. When deleting file second time error unique constraint (BLOG_HTTP410_PK) violated is raised.
Workaround: Run in SQL Workshop alter table blog_http410 drop constraint blog_http410_pk /
alter table blog_http410 drop constraint blog_http410_pk /
Workaround applied to APEX 5 application export
Workaround:
Run in SQL Workshop
alter table blog_http410 drop constraint blog_http410_pk
/
Workaround applied to APEX 5 application export