Q: problems upgrading from mavericks to el capitan

There are no problems as long as you have an up-to-date version of iPhoto, bought at the Mac App Store. As always, back up first.

No - there are things it helps to do and to know - these links provide that information

Notes on Migrating an iPhoto Library from iPhoto to Photos for Mac

How Photos handles content and metadata from iPhoto and Aperture - Apple Support

Moments in Photos are the New Events

Photos 1.5 vs iPhoto 9.6.1:  Features and Capabilities

LN

     You are welcome

LN

I have heard of problems with the photo library migration from iphotos to photos, are there problems with it?  This is the only thing keeping me from upgrading to el capitan, all my photos are in iphoto on mavericks. Thanks!!

Are you now using iPhoto 9.5.1? Then you can probably update iPhoto to version 9.6.1, that runs on El Capitan, and you will be able to open your iPhoto Library in iPhoto side by side with Photos. That will make the migration easier, because you can compare the libraries.

See Barney's user Tip on how to update and to check, if you will be able to: 

  Can't Update iPhoto because it is not available in the App Store

https://discussions.apple.com/docs/DOC-8431