Cannot read properties of null (reading 'removeChild')

[georgebotley]

Affected Version

undefinedoffset/sortablegridfield              2.0.x-dev fff3f08 

Description

GridField has over 152 items, split across 11 pages. User is unable to drag items from page 11 through to any page number lower than 9. i.e. Moving item to page 8 fails. Error in console on attempting this is:

Uncaught TypeError: Cannot read properties of null (reading 'removeChild')
    at e.<computed>.<computed>._clear (vendor.js?m=1614547258:1:2039537)
    at e.<computed>.<computed>._clear (vendor.js?m=1614547258:1:1957167)
    at e.<computed>.<computed>._mouseStop (vendor.js?m=1614547258:1:2023251)
    at e.<computed>.<computed>._mouseStop (vendor.js?m=1614547258:1:1957167)
    at e.<computed>.<computed>._mouseUp (vendor.js?m=1614547258:1:1965213)
    at e.<computed>.<computed>._mouseUp (vendor.js?m=1614547258:1:1957167)
    at HTMLDocument.i._mouseCapture._mouseDistanceMet._mouseDelayMet._mouseUpDelegate (vendor.js?m=1614547258:1:1964394)
    at HTMLDocument.dispatch (eval at e.exports (vendor.js?m=1614547258:1:1), <anonymous>:2726:92)
    at HTMLDocument.eventHandle (eval at e.exports (vendor.js?m=1614547258:1:1), <anonymous>:2384:112)

Steps to Reproduce

• Create GridField with lots of items
• Move item from last page to a page mid-way into the list of pages.