We would recommend trying to remove the channel. Then trying to perform a factory reset on your device. Then once the device is setup again, try adding the channel back again and seeing if your issue is resolved.
I did as you asked; I deleted the channel and put it back up and it worked fine for a day. The day after that, the message that I had run out of space occurred again. We have the 3900X model. Was able to put back Hulu, Nexflix, Amazon Prime, and Viki and those work fine, but the problem now only occurs when we try to use YouTube. Tried it again just now to see if it was still happening, and it is. Thank you for trying to help.
If you are still unable to resolve the issue, please send me a PM with your Roku account email address, and include the serial number of the Roku device from Settings>System>About along with a summary of the issue you are experiencing. I'll be able to assist you further from there.
I also have the same problem. Have updated from old Roku LT box to a Roku Xpress and since owning it i have had this problem which i never had with my LT box. I would hate to think how many Factory resets i have done since having this problem but most apps are not loading now. Funny thing is, apps that did load successfully before do not open and a few others that previously did not open now do. I am sure this is a software issue or bug which surely must be resolved by Roku.
How many channels do you have installed on your Roku device? We would recommend removing any unused channels from your Roku device, then trying to perform a factory reset to see if that resolves the issue you are experiencing.