SYMPTOM:
In Strategy Web 9.4.x, an ‘Access denied’ error message is displayed when exporting a report to HTML via URL API:

Access denied The following privilege is required to access the resource you requested: WebExportToHTML (4)
http://localhost/MicroStrategy/asp/Main.aspx?server=SERVERNAME &Project=Strategy+Tutorial &Port=0 &uid=Administrator &pwd= &src=mstrWeb.3012&evt=3012 &reportID=EB3CD5D14F4C8C77782AC0882C986B8D &exportFormatGrids=htmlGrids
http://localhost/MicroStrategy/asp/Main.aspx?server=SERVERNAME &Project=Strategy+Tutorial &Port=0 &src=mstrWeb.3012&evt=3012 &reportID=EB3CD5D14F4C8C77782AC0882C986B8D &exportFormatGrids=htmlGrids &usrSmgr=0.000000011209eb04d3689335e915ec8983b16...
http://localhost/MicroStrategy/asp/Main.aspx?server=SERVERNAME &Project=Strategy+Tutorial &Port=0 &uid=Administrator &pwd= &src=mstrWeb.3067&evt=3067 &group=export&fastExport=true &reportID=EB3CD5D14F4C8C77782AC0882C986B8D &reportViewMode=1&showOptionsPage=false&defaultRunMode=htmlGrids
http://localhost/MicroStrategy/asp/Main.aspx?server=SERVERNAME &Project=Strategy+Tutorial &Port=0 &uid=Administrator &pwd= &src=mstrWeb.3130&evt=3130 &documentID=D9F2A9404C2626D3C92EDF826EEF0B7A