I have run into this same issue right now, and it is like cat and mouse game 
WHMCS creates an account in DNP successfully and DNP deletes it almost instantaniously.
In my case I am not trying to recreate existing resources on DNP nor I am trying to create non existent resources in DNP, Absolutely no errors are shown in DNP Audit Log. But the created account is deleted.
In the Windows Event Viewer I see error as below.
General tab:
[8/1/2008 2:00:04 PM] ERROR: Trying to create folder C:\HostingSpaces\userspace
System.Exception: Exception of type 'System.Exception' was thrown.
Details tab:
- System
- Provider
[ Name] DotNetPanel
- EventID 0
[ Qualifiers] 0
Level 2
Task 0
Keywords 0x80000000000000
- TimeCreated
[ SystemTime] 2008-08-01T08:30:04.000Z
EventRecordID 113
Channel DotNetPanel
Computer WIN-SERVEEHH
Security
- EventData
[8/1/2008 2:00:04 PM] ERROR: Trying to create folder C:\HostingSpaces\userspace System.Exception: Exception of type 'System.Exception' was thrown.
Server Specs:
OS: 2008 Server Std 32bit
DNS, FTP no 3rd party software used
Mail server hMailServer 4.4.1 - Build 273
MS SQL Express 2005 with advanced services
Please investigate this issue and help me as things like this are just acting like stoppers. Please don't just ignore this saying we do not support 3rd party product. The 3rd party product is using DNP API and creating accounts without any errors. It is DNP that is deleting the created account.
I am able to manually create the same account with same resources in DNP without any error, DNP is not deleting this manually created account.
Help is appreciated thanks.