Programs like Nokia NbuExplorer can work both with the NBU and NBF files. However it doesn't seem to be possible to convert between each another. You can just recover whatever you need from the backup, like contacts and use it in your new phone. But a successful direct nbu to nbf conversion is unlikely.
This conversion entry was verified by us and conversion was flagged as wrong or not possible.
Usually this happens when the conversion would try to convert different types of data between each other, such as audio to image, or it is not possible because incompatibility between programs, caused by closed file formats, very limited support etc.
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