Here is an update on my situation. I allowed the install to complete and then tried re-porting my characters.
I am missing ALL of my heads and skins for each character and both vehicle types with the exception of the appearance pack heads and skins; ie, psycho party pack. It appears that ALL content that is account locked did not transfer for me including BA rank (which is a widely known issue).
On a side note, I am still getting the same message that I am missing DLC and that it is currently not available and to try again later. It seems I am missing several items that seem to be tied to the missing dlc. For example, my Legendary Anarchist and Legendary Mechromancer Coms are no longer showing in inventory, same goes for my Sand Hawks and Pimpernels to name a few.
This would insinuate that CSAHPB dlc is missing, yet I show the locations on the fast travel. The Coms were included with the introduction of the Pearls if I remember correctly, perhaps the dlc is bugged somehow? However, that wouldn’t explain the lack of skins/heads.
Also, there is a very significant decrease in frame rate when opening the inventory menu even after the install was complete.
Another small issue, has anyone else noticed that all game audio will cut off after a while? I have a set of Astro A40s that run through the headset adapter. When this happens I still have party chat through the headset, but no game audio. This is the first time I have had this happen with my set up and at first I thought it could be the connection to the adapter, the cable, ect until another person in my game mentioned that she also lost all game audio and her subtitles.
@estevamlima It seems these items are not available for me to use in game. I had a similar problem before when I had to get a new xbox 360 and transferred all of my game data to the new hard drive for Borderlands 2. After playing for a while, the game flagged my system for having dlc that wasn’t registered to the console. Thus, all of the DLC related items were not showing in inventory and I received the same “Missing DLC” message. Upon re-downloading all of the DLC on the new console the problem was resolved. I wonder if Microsoft Licencing protocols may have something to do with the problem? It would make sense because the DLC would not be registered to that console… Just talking out of my head, but there seems to be some correlation.