Problem Drawing Lines in the Dynamic Lightning Layer

Hi, I'm encountering the next bug. I've started to paint my first Dynamic Lightning page. I was editing the walls, deleted all walls to start over and after painting some walls, the client stopped showing the lines I wanted to draw. After reloading the page, I see all the lines I've drawn (but which did not showed up). Now I'm unable to delete these lines. Starting the Chrome developers console, I see a lot of "Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'setIconVisibility')  at vtt.bundle.js:7668:34837 " error messages. Is this a know problem? Are there any workarounds, I could use? Thanks in advance, Torsten

Here is a screenshot of the situation:

Hi Torsten! For something this technical, your best bet is to contact the dev team with a  Help Center Request . The forums are more used for community-level help. Filing the request (along with your  Console Log ( Chrome , Firefox),  preferably in editable, searchable text copy-paste), along with the name of the game, and the page in question, will create a ticket with the information they will most likely need.

As a short term thing, perhaps using fewer torches during the wall-drawing phase will help. I can see 20+ torches just in that segment of the map. Many light sources is not something the VTT handles well. 

Thanks to both of you. I've managed to somehow, remove all the walls and to get Roll20 to accept new walls.