If you are upgrading from version 4.x you need to make sure you have upgraded to version 4.9.5 before upgrading.

Potentially Breaking Changes Upgrading From Version 4

• Read through the upgrade documentation found here before continuing as there are a number of major changes.
  
• Forums have been removed. HelpSpot will provide an export option and we recommend moving forums to one of the many purpose-built forum platforms. Here at Userscape we use Discourse (https://www.discourse.org/).
• Tokens in templates and responses are now delimited by double “{“ characters. Existing responses and templates will be automatically converted. However, if you are using an external text macro tool, for example, you may need to make updates.
• Admin Themes have been removed and have been replaced with custom admin JS and CSS settings.
• Custom portal templates need to be updated

Bug Fixes

• Security Fix