I have SharePoint 2010 and I going to update it to 2013. I deployed SP 2013 Server and mounted copy of SP 2010 database - everythink ok! Then, I mounted the same copy of SP 2010 to another web-application and updated interface to 2013.
After update, I found problem: some Excel files doesn't opens with error "long file name 218 characters etc."
Yes, I use Cyrillic URLs and filenames, I use long paths and filenames, but I can't undertand: non updated DB works fine, updated DB works a half.
Error message (sorry, in Russian):

Systems with Office 2013 - file doesn't open.
Systems with Office 2010 and "Office common components 2013" - file doesn't open.
Systems with Office 2010 only - file opens fine.

• Edited by Peter Koreshkov 46 minutes ago

add: remove office 2013 common components and installing office 2010 common components - helps.

But no need any action for database, that was not updated to 2013 interface.