Hi,
since the release of Minecraft bedrock on June 21, 2018 I am not able to use my previously purchased DLC (Egyptian Mythology).
When I try to use this pack, the screen turns black and pink. It happens with already existing and new created worlds.
Thank you for your report!
However, this issue has been closed as a Duplicate of MCPE-34633.
Please add a vote and any new information to the main ticket, which will be updated accordingly.
If you have not, you might like to make use of the search feature before making a new ticket, as it's likely that the issue has been reported already.
Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Feedback – 📖 Game Wiki