I’m using LRT7, and am having problems trying to add tilt (or animated crop). The process I’m following is as below – am I doing something wrong somewhere?

1. I create 2 different keyframs in LRT (one at the start and one at the end).
2. When I come to the step of editing keyframes in Lightroom, I crop the 2 keyframs differently (both 16:9), but leave all the other images unchanged.
3. In LRT, I have the ‘Crop top’ and ‘crop bottom’ columns checked, and the values in the se columns are gradually chaging through the sequence.
4. When I then come to the ‘Export & Render (Lightroom)’ step, I get an error message in Lightroom that there are different crop aspect ratios.
5. I then render them using LRT, and I find that rather than gradually transition between the keyframes, the crop stays the same the whole time (until the final keyframe, when it suddenly jumps to the crop of the second keyframe).

It's logical, if you force the transition to do only the top and bottom columns, that the aspect ratio changes.

Please always make sure that all 5 crop columns are checked (including rotate) when you apply a crop transition. LRTimelapse will then try to make sure that the crop doesn't change the AR.
There is also an expert tips tutorial on https://lrtimelapse.com/tutorial/expert where I explain the crop animation, you might want to check that out!