For those using the M3U4U for playlist management and custom channels.
As of just a few days ago, M3U4U made some changes that now require you to have a dropbox account and do some authentication with dropbox in order to use their free service.
I had one custom channel that was using a URL based playlist that I was managing there. I was using a separate link for the EPG data for this custom channel.
The folks at M3U4U inserted a tag in the M3U at their site to “Visit M3U4U.com”. The stream in my custom channel still worked, but my EPG that I was using for that channel - Weekly Game Previews appeared to get hosed in the channels guide.
I fixed my use case by hard coding my one channel and bypassing M3U4U..
However, if anyone is using a huge playlist and linking that back into a custom channels source, you might want to update your M3U4U account to adhere to their dropbox requirement.