We have had a similar issue this season with seeing the "Rebooting" message which never finishes while trying to re-image the cRIO. Although I understand that there are others who might disagree on the necessity of some of the steps in our method, this is what has reliably been successful for us this year. [Note that we had not seen these issues in previous years.]
1). Make sure you have your wireless turned off (disabled) on your laptop.
2). Make sure that you have your IP address configured to 10.xx.yy.5 and make sure that there are no other additional/alternate IP addresses setup. (You can check this and remove them by clicking on the Advanced button from the TCP/IPv4 Properties panel).
3). Reboot the laptop if you had to make any changes in the above settings. Not exactly sure why but it definitely makes a difference, perhaps there is residual connection otherwise.
4). Connect directly from the laptop to the cRIO using a CROSSOVER ethernet cable.
5). Use the cRIO imaging tool provided and follow the instructions for the configuration you want (ie. C++, netconsole, etc).
Hope this helps.
