Can't save or edit
In this article
Possible causes on WordPress
Another option to debug this problem is to run a plugin/theme conflict test and check the problem still happens after each plugin you enabled.
Possible causes on Joomla
You could try to go to your Extensions → Plugins, filter out the
systemplugins, and unpublish them (except the
Smart Slider 3 System Plugin). If the error goes away after you disabled these plugins, one of them caused the issue. Start turning them back on one by one to see which one is responsible.
Try to turn on the
Alternative Save Slideoption at the Global settings → General. It can help with problems when you can't save because of a server setting, like at some hosts have a setting to prevent saving down URLs.
Usually servers are limiting the size of what you are trying to save, so if you managed to save so far, just you made your slider bigger, then this will be your problem and you should contact your server host to increase the memory_limit on your server. Also you could ask them to check the error log, which could also tell the cause.
406 - Not Acceptable [...] This error was generated by Mod_Security
Similar error message:
406 - Not Acceptable! An appropriate representation of the requested resource could not be found on this server. This error was generated by Mod_Security.
Mod_Security errors mean, that your server host has some security setting, which doesn't allow certain contents to be saved down by your website. This Mod_Security should be turned off at the server, because it is a wrong configuration, as you should be able to save down any content you want to. In most cases there aren't even workarounds for the errors this Mod_Security limitation causes.
So you should contact your server host and ask them to turn off Mod_Security on your server!