Shortly after Apple released iOS beta 6 of iOS 11.4 they revoked the developer profile so non-registered developers were unable to use the profile. Today 24 hours after releasing iOS 11.4 to the public Apple has released iOS 11.4.1 beta 1 to developers. For those who are now unable to install the beta profile there is a workaround, and at the end you will be able to get the new 2.2GB software update.
- Go to setting > date and time and change your date back (I set mine 2 months back)
- open safari and click here.
- Go to iOS 11 beta and choose your phone model click go
- Skip the Ad and then click allow
- Type in your passcode and install the profile
- Go to settings > General > Software update to register you have an update and hit download
- Whilst Downloading Go back to setting > date and time and change your date back to automatic
- Now go to back to settings > General > Software update and wait whilst your update installs and restart your device
- You now have the latest beta installed
Please Note during this process you may come across several error messages as your device date is older than app settings.