I have been trying to solve a problem that I was having when placing certain effects in a particular row. After some hours of frustration, updating version, and some I can't remember and cursing too, I finally deleted the row and re-inserted the model. I believe that I have got through that problem now. But others have appeared. Some how during my trying to fix something I lost all the timing arks in the sequence. Now I can't make any more marks. I also can't copy and paste effects from a row so that I can paste them in the row that I had to delete.
The version I am running is 2018.33 - 64.
I know what I did now, I deleted the timing track. Don't ask me why, I didn't know what I was doing is all I can say. I'm now trying to figure how to get a timing track back in the sequence. And figure out the copy and paste thing