That’s what I was trying to find out: Whether it was a profile or system issue and apparently it’s a profile issue. 
My further recommendation is to just forget about the old profile and copy not move your Documents, Music, … folders over to the new user and disable the old user and delete the old user’s home directory with all its files in 6 months time…
If you would not have enough space to do that, just copy Documents from old to new, delete documents, copy Music, delete Music etc… then disable user and delete user in 6 months.
Note 1 Don’t delete the old user. Just delete its home directory, just in case that in 1 year or so you still find a file from the old user you’ll still see its name instead of an ID (and that takes just a few KB on your system)
Note 2: If you need any specific help with any of the above, please leave another response.