Zender v1.1.2

This is an update to fix most of the discovered bugs on v1.1
You can download here.
The release version is v1.1.2 on github, if any issues will be encountered, please reply to this thread immediately.
After updating, please delete all the contents of system/storage/cache/
Changelog v1.1.2:

• Added language error handler
• Updated documentation
• Fixed admin impersonate exit
• Fixed languages collation issue
• Fixed dashboard array boolean bug
• Fixed API key handling error
• Fixed registration not working
• Fixed import contacts limiter
• Fixed vouchers not working
• Fixed updater errors
• Fixed installer errors
• Fixed add page errors