GE Proficy Edition 7.0 question

I'm pretty much brand new in the plc world and i'm struggling a little bit. I recently took a "hands-on" test for a possible promotion at my job, and one of the skills i was required to demonstrate was to write a small amount of logic on a GE series 90-30 plc with the Proficy Machine Edition software. I ran into an unexpected problem on my test...when i tried to insert the OTE instruction in my ladder logic, it wouldn't accept it, and all it kept doing was completing the rung without adding my instruction. I have been going over the PDF and the help sections in the software to try and figure out how to remedy that problem if i see it again, but i've not been able to find an answer. Can anyone help me with this?

Please describe the steps you took when trying to insert the instruction. From the way you phrased your question, I expect you're more familiar with RS Logix. The biggest hurdle to overcome when trying to learn a new brand is the inclination to try to make the new system behave just like the one you're familiar with.

I know next to nothing about modern AB programming but if you were looking for a GE equivalent to a bit that is ON when a Timer is Enabled there isn't a dedicated BOOL in GE for that purpose. There is a bit in the Control Word of a Timer but I don't recommend using it as that tends to confuse troubleshooting.
Instead I suggest setting up your 'Timing' logic to an internal bit i.e. %Mxx, then use that as the Enable bit to the Timer Function block and anywhere that it may be needed. Likewise there is no 'Done' bit unless you assign one as an output of the Timer Function block.