maths have 12 period per week

[lavert]

maths have 12 period per week, system cannot allow me to generate timetable with this

[Volker Dirr]

why not? what is the error report?

[Volker Dirr]

ah... maybe you have only a 5 day week and you add as 1+1+1+1+1+1+1+1+1+1+1+1? that is of yource not very wise if you also check the "consecutive" option, because you have 12 subactivites, but you can schedule max 2*5=10.
so in that case you must do at least an activity with 2+2+1+1+1+1+1+1+1+1. (so also 12 hours per week, but only 10 subactivities)
but i recommend to reduce the split number a bit more, especialy if you use the consecutive option. (but that depend on your dataset.)
on the other hand you can simply uncheck the consecutive option.