Hey Ani_,
I've been working with Adobe products for a long time and typically when you come across an error that has anything to do with a XML file export problem its due to things such as effects you may have added in, color corrections, cross fades or any type of video transitions between clips. Remember your work flow should be
Import your footage into Premiere Pro
Name your clips (helps find things later on)
Place clips on time line in the order you wish (ONLY MAKE CUTS don't add anything, transitions color effects nothing)
Then once your clips are all placed on the timeline in your correct order you then EXPORT> Final Cut Pro XML
Now you can bring this into other programs for color grading or whatever else your going to do. You will notice you have no errors on the export.
Once your done doing what your doing to the clips in another program (for example: Divinci Resolve color grading) you can then export them back to your main project then add your effects and transitions.