Description
When you tried to install Episerver.ConnectForCampaign package 3.0.0. and upper, you will get below error message and the installation fails.

Steps
Installed the following packages & versions (latest versions) into a Foundation site:
Package | Version |
EPiServer.ConnectForCampaign | 3.0.0 |
EPiServer.ConnectForMarketingAutomation | 5.7.0 |
Website refuses to start due to missing classes (cache-related) in EPiServer.ConnectForMarketingAutomation. It was saying that the caching classes from ConnectForMarketingAutomation can’t be found in the DLL.
Cause and Solution
The interface ICacheService has been removed in EPiServer.ConnectForMarketingAutomation 5.7.0. Ideally, the version should have been made 6.0.0. If any methods in this interface are being used in ConnectForCampaign, they should be replaced by the methods in ICacheHelper.
Short-term fix: The highest version of ConnectForMarketingAutomation should be made 5.6.3 in the dependencies of ConnectForCampaign.
Additional comments.
Please contact support if you have further questions.