Exception when using freetext tool

I am getting following exception when using freetext tool

message:“TypeError: Cannot read property ‘getBoundingClientRect’ of null”
stack:"Error: TypeError: Cannot read property ‘getBoundingClientRect’ of null
at z (http://localhost:4200/lib/core/CoreControls.js:187:355)
at http://localhost:4200/lib/core/CoreControls.js:458:148
at Array.forEach ()

Hey there!

I cannot reproduce this error. Are you making any changes to any classes related to the FreeTextTool? Any code samples would be great.