An associated issue is that
if you compile using ArduinoJson library on WebIDE - it will work.
if you compile using ArduinoJson library on Workbench locally - it will work.
if you compile using ArduinoJson library on Workbench Cloud compile - it will fail.
The reason is that ArduinoJson uses .hpp files in its (many) files of its library and the .hpp are not considered in the building process