"All SSH authentication methods failed" when registering Linux host with PEM file in ArcGIS Monitor

Error Message

The following error is returned when registering a Linux host in ArcGIS Monitor and checking the "SSH Key Credentials" box, as shown in the image below:

All SSH authentication methods failed.

Cause

ArcGIS Monitor uses the SSH key stored in the following location to gain access to the Linux machine:

C:\Users\<account running ArcGIS Monitor>\.ssh

A PEM file is commonly used to access Linux machines hosted in AWS. A PEM file can contain any combination of a public key and a private key. The error message is returned because ArcGIS Monitor is expecting to use an SSH key to connect to the Linux machine instead of a PEM file.

Solution or Workaround

A few additional steps are necessary when using a PEM file instead of an SSH key to register a Linux host:

1. Make sure the PEM file is located in the C:\Users\<account running ArcGIS Monitor>\.ssh folder.
2. Make a copy of the PEM file.
3. Rename the copy to id_rsa (no file extension).
4. Attempt the registration workflow again.