I have had this problem when I added a new variable in the structure, I tried to fix it with the solutions I saw in this post, but they did not work for me.
I duplicated the structure and tried to erase the original and replace the references with the duplicate, then a miracle happened, the editor gave me many errors and despite not closing it, it showed me a message with all the BPs that were affected and recommended me to close without saving, when I reopened the editor everything worked correctly and I was able to cook the project …