I recently received a bug report from a client and long-time appfarm user dplan/e2p regarding a crash when trying to change the estimated duration of an element in the gantt chart. When I click on an element, we can adjust the estimated duration of the task. As a default each element start with the value 0, and for any number less than or equal to 0, the element will be visualized as a milestone, but when changing this to a positive integer e.g 1, 5 or 10, the element will turn into a rectangle and stretch over the specified duration. The crash occurs when changing the duration from 0 or a negative number to any positive integer. However, once the page is reloaded the element now has the correct shape (rectangle) and it can be changed to another duration without a crash.
See the following 3 images.
Starting point, here I click on the estimated duration and change it to “1” and immediately the site crashes. See the second image.
Image of the crash details referencing a type error with the following trace:
Trace
TypeError: Cannot read properties of undefined (reading 'animate')
at e.drawPoint (https://e2p-dev.appfarm.app/assets/6996.42bfa55ce49a8c5479d6.js:1:77999)
at e.drawPoint (https://e2p-dev.appfarm.app/assets/6996.42bfa55ce49a8c5479d6.js:1:125894)
at e.drawPoints (https://e2p-dev.appfarm.app/assets/6996.42bfa55ce49a8c5479d6.js:1:78757)
at t.render (https://e2p-dev.appfarm.app/assets/7568.5bb0cc3a2d0a37cc543e.js:3:227618)
at t.redraw (https://e2p-dev.appfarm.app/assets/7568.5bb0cc3a2d0a37cc543e.js:3:228019)
at https://e2p-dev.appfarm.app/assets/7568.5bb0cc3a2d0a37cc543e.js:3:183157
at Array.forEach (<anonymous>)
at t.redraw (https://e2p-dev.appfarm.app/assets/7568.5bb0cc3a2d0a37cc543e.js:3:183108)
at t.setSize (https://e2p-dev.appfarm.app/assets/7568.5bb0cc3a2d0a37cc543e.js:3:189817)
at t.update (https://e2p-dev.appfarm.app/assets/7568.5bb0cc3a2d0a37cc543e.js:3:200700)
at https://e2p-dev.appfarm.app/assets/7568.5bb0cc3a2d0a37cc543e.js:1:2257
at oD (https://e2p-dev.appfarm.app/assets/react.8e976460f78afa7d1303.js:18:14466)
at oK (https://e2p-dev.appfarm.app/assets/react.8e976460f78afa7d1303.js:18:20846)
at e (https://e2p-dev.appfarm.app/assets/react.8e976460f78afa7d1303.js:18:41397)
at https://e2p-dev.appfarm.app/assets/react.8e976460f78afa7d1303.js:18:41408
at uD (https://e2p-dev.appfarm.app/assets/react.8e976460f78afa7d1303.js:18:41909)
at uw (https://e2p-dev.appfarm.app/assets/react.8e976460f78afa7d1303.js:18:25318)
at x (https://e2p-dev.appfarm.app/assets/react.8e976460f78afa7d1303.js:18:60736)
at MessagePort.R (https://e2p-dev.appfarm.app/assets/react.8e976460f78afa7d1303.js:18:61266)
Then once the page is reloaded we can see that the same element now has the correct shape.
I have done some debugging and found out that it is not any of the actions that are causing this crash (as I tested while disabling almost everything), but many of the system variables are functions and I was not able to test if any one of those calculations was the cause, but due to the error being an undefined “animate” I suppose it might be a bug related to the gantt chart itself.
As a temporary workaround we have set all the elements to be milestones and this prevents the crashing, so we are quite certain that it is related to the animation changing between the milestone and the rectangle.
Please let me know if there is any other information you need to help me resolve this issue. 
Best regards,
Emil
