Error: Keyset does not exist

[daniel-cues]

I'm attempting to authenticate using a PFX file I made from a certificate and key.
However Rubeus returns this error:

   ______        _                                                                                                              
  (_____ \      | |                                                                                                             
   _____) )_   _| |__  _____ _   _  ___                                                                                         
  |  __  /| | | |  _ \| ___ | | | |/___)                                                                                        
  | |  \ \| |_| | |_) ) ____| |_| |___ |                                                                                        
  |_|   |_|____/|____/|_____)____/(___/                                                                                         

  v2.3.2                                                                                                                        

[*] Action: Ask TGT                                                                                                             

[*] Got domain: **redacted**                                                                                                     
[*] Using PKINIT with etype rc4_hmac and subject: CN=*.**redacted**
[*] Building AS-REQ (w/ PKINIT preauth) for: '**redacted**\admin'                                                                
[*] Using domain controller: **redacted**                                                                              

[!] Unhandled Rubeus exception:                                                                                                 

System.Security.Cryptography.CryptographicException: Keyset does not exist                                                      

   at System.Security.Cryptography.Pkcs.PkcsUtils.CreateSignerEncodeInfo(CmsSigner signer, Boolean silent, SafeCryptProvHandle& 
hProv)                                                                                                                          
   at System.Security.Cryptography.Pkcs.SignedCms.Sign(CmsSigner signer, Boolean silent)                                        
   at System.Security.Cryptography.Pkcs.SignedCms.ComputeSignature(CmsSigner signer, Boolean silent)                            
   at Rubeus.PA_PK_AS_REQ.Encode()                                                                                              
   at Rubeus.PA_DATA.Encode()                                                                                                   
   at Rubeus.AS_REQ.Encode()                                                                                                    
   at Rubeus.Ask.InnerTGT(AS_REQ asReq, KERB_ETYPE etype, String outfile, Boolean ptt, String domainController, LUID luid, Boole
an describe, Boolean verbose, Boolean opsec, String serviceKey, Boolean getCredentials, String proxyUrl)                        
   at Rubeus.Ask.TGT(String userName, String domain, String certFile, String certPass, KERB_ETYPE etype, String outfile, Boolean
 ptt, String domainController, LUID luid, Boolean describe, Boolean verifyCerts, String servicekey, Boolean getCredentials, Stri
ng proxyUrl, String service, Boolean changepw, String principalType)                                                            
   at Rubeus.Commands.Asktgt.Execute(Dictionary`2 arguments)                                                                    
   at Rubeus.Domain.CommandCollection.ExecuteCommand(String commandName, Dictionary`2 arguments)                                
   at Rubeus.Program.MainExecute(String commandName, Dictionary`2 parsedArgs)          

I haven't seen this error mentioned in any other Issue, what could be happening here?