HTML and or ubbcode markup must be enabled in the permissions of the control panel. it is set per group.
Allowing html posts has always been frowned upon.
If the poster inserts bad html it could break the forum.
Let alone adds a security risk.
anyway
goto
control panel/Group Management » Forum Permissions for each group desired one at a time.
select
Can post using HTML
place a 1 in each forum you want it allowed
do the same for
Can post using Markup/UBBCode
select the update button.
Repeat for the next desired group.
Also wiki is your friend
