Hi,
Upgraded K2 this afternoon & am now getting the following when creating/editing a K2 item

Fatal error: Cannot declare class upload, because the name is already in use in /home/...../public_html/administrator/components/com_k2/lib/class.upload.php on line 624

Joomla! Info:
PHP Version 7.0.22
Web Server Apache
WebServer to PHP Interface cgi-fcgi
Joomla! Version Joomla! 3.7.5 Stable [ Amani ] 14-August-2017 12:09 GMT

MySQL version 5.6.36-82.1-log
GD image library bundled (2.1.0 compatible)
Multibyte string support Enabled
Upload limit 128M
Memory limit 768M
Open remote files (allow url fopen) Yes

Any suggestions?

Thanks,
Eddie

Which other extensions and K2 plugins are you using?

Which other extensions and K2 plugins are you using?

Hi,
Thanks for quick reply - appreciated.

K2 Modules

mod_k2_comments Installed
mod_k2_content Installed
mod_k2_tools Installed
mod_k2_user Installed
mod_k2_users Installed
mod_k2_quickicons (administrator) Installed
mod_k2_stats (administrator) Installed

K2 Plugins

Finder - K2 Installed - Enabled
Search - K2 Installed - Enabled
System - K2 Installed - Enabled
User - K2 Installed - Enabled

Third-party Extensions

AllVideos (plugin) Installed
Simple Image Gallery Pro (plugin) Not Installed

Components
Akeeba Backup
JCE Editor Pro
JotCache
K2
Post-installation Messages
Regular Labs - Extension Manager
Unite Revolution Slider 2

Thanks,
Eddie

Can you try disabling extensions one by one to see which is causing this issue?

Start with Unite Revolution Slider 2

Hi,
Disabled all, starting w/ Unite.
Same problem.
Cheers

Hi,

Looking at K2 categories I get the following warning:

Warning: Declaration of K2ElementExtraFieldGroups::render() should be compatible with K2Element::render($layoutId, $data = Array) in /home/..../public_html/plugins/k2/mefgfork2/elements/extrafieldgroups.php on line 14


Cheers,

I cannot verify this issue, nor has it been reported by other users using 2.8 or 2.8 DEV. Is this issue present in other sites as well?

Sorry,
2 more warnings when editing K2 category:

Warning: Declaration of K2ElementMultiSelects::render() should be compatible with K2Element::render($layoutId, $data = Array) in /home/.../public_html/plugins/k2/mefgfork2/elements/multiselects.php on line 0

Warning: Declaration of K2ElementImages::render() should be compatible with K2Element::render($layoutId, $data = Array) in /home/.../public_html/plugins/k2/mefgfork2/elements/images.php on line 0

Cheers,

These are coming from a 3rd party K2 extension.
Try disabling this extension (mefgfork2) as well.