Cannot read property 'bottom' of null

TypeError: Cannot read property 'bottom' of null

at n.<anonymous> (https://usr/app-service.js:4087:720)

at Function.<anonymous> (https://lib/WASubContext.js:2:1101698)

at https://lib/WASubContext.js:2:111972

at https://lib/WASubContext.js:2:1101988

at r (https://lib/WASubContext.js:2:1101961)

at https://lib/WASubContext.js:2:1102115

at https://lib/WASubContext.js:2:1816472

at r (https://lib/WASubContext.js:2:1752826)