Similar problem here: when I click "Message this owner" the message center looks OK, but sending is impossible due to Javascript errors. My browser is the latest Chrome. Hard refresh doesn't help. The only workaround is not using the "Message this owner" link and searching for the owner manually. The error I get is listed below.
edit-panel.js:125 Uncaught TypeError: Cannot read property 'uploader' of undefined
at r._setExpandedState (edit-panel.js:125)
at r._childViewEventHandler (vendor?v=eEs04XxUqubTHodEji5NgsvVnaBAGcuql-MQt3RXxpY1:1)
at l (vendor?v=eEs04XxUqubTHodEji5NgsvVnaBAGcuql-MQt3RXxpY1:1)
at g (vendor?v=eEs04XxUqubTHodEji5NgsvVnaBAGcuql-MQt3RXxpY1:1)
at e (vendor?v=eEs04XxUqubTHodEji5NgsvVnaBAGcuql-MQt3RXxpY1:1)
at r.u.trigger (vendor?v=eEs04XxUqubTHodEji5NgsvVnaBAGcuql-MQt3RXxpY1:1)
at r.y (vendor?v=eEs04XxUqubTHodEji5NgsvVnaBAGcuql-MQt3RXxpY1:1)
at r.triggerMethod (vendor?v=eEs04XxUqubTHodEji5NgsvVnaBAGcuql-MQt3RXxpY1:1)
at r.onTextChange (edit-text.js:66)
at r.onAttach (edit-text.js:49)
