Old solution doesn't work on new SharePoint Online

Hello,

My solution, that was developed on old SharePoint Online 2010, cannot be activated as usual.

Is there any changes behind that prevent package from activated?

It throws null reference exception here:

Exception rethrown at [0]: 
   at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
   at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
   at Microsoft.SharePoint.SPField_SubsetProxy.set_Description(String value)
   at Microsoft.SharePoint.SPField.Description__set(String value)
   at Microsoft.SharePoint.SPField.set_Description(String value

Thanks,

Thanh Dang Tuan