Yeah that is the Problem… When ever you are using Format Method the string content should be {0} ,{1} like this.
but unfortunately first only it should be there. next time that will changed with values …So next time nothing will replace
to avoid this… you have to assign one more variable …ex(Str_temp) in this variable store the template of body string
then
Put assign activity like below
Str_EmailBody = String.format(Str_temp,row(“Supervisor”),row(“ss”))