I am trying to install Amazon CTI support in Service Cloud.  My account is Developer Edition and should have necessary rights.  But I encountered an error by following below steps:

Reproduce Steps:
1. Login as an account with Developer Edition 
2. In Service cloud, select <gear icon> -> Service Setup -> View All -> Add Phone Support
3. Select Amazon Connect CTI Adapter: CTI -> click Next
4. An message said:
Although there is a message said "Everything's installed, so now we can connect your phone to Salesforce.", I got another error meessage: "Something's not right with your CTI vendor's metadata.  Ask your CTI vendor for help.".

Anyone knows the potential cause and resolution?

I am trying to install Amazon CTI support in Service Cloud.  My account is Developer Edition and should have necessary rights.  But I encountered an error by following below steps:

Reproduce Steps:
1. Login as an account with Developer Edition 
2. In Service cloud, select <gear icon> -> Service Setup -> View All -> Add Phone Support
3. Select Amazon Connect CTI Adapter: CTI -> click Next
4. An message said:
Although there is a message said "Everything's installed, so now we can connect your phone to Salesforce.", I got another error meessage: "Something's not right with your CTI vendor's metadata.  Ask your CTI vendor for help.".

Anyone knows the potential cause and resolution?