After upgrading from 1.6.3 to 2.9.0, I'm getting the following errors when I try to bring up the Site Upload Preferences:
A PHP Error was encountered
Severity: Warning
Message: array_merge() [function.array-merge]: Argument #2 is not an array
Filename: models/file_upload_preferences_model.php
Line Number: 111
A PHP Error was encountered
Severity: Warning
Message: array_merge() [function.array-merge]: Argument #2 is not an array
Filename: models/file_upload_preferences_model.php
Line Number: 111
A PHP Error was encountered
Severity: Warning
Message: Cannot modify header information - headers already sent by (output started at /home/mysite.com/system/codeigniter/system/core/Exceptions.php:170)
Filename: core/Common.php
Line Number: 442
My issue started with the fact that I was using Mark Hout's File extension, and I was going to try to implement this fix:
https://ellislab.com/forums/viewthread/218268/
and I needed to get the upload directory's ID from the File Upload Preferences.