Conflict With Other Spyware And Malware Programs

I know that when installing Bitdefender all other antivirus, spyware, and malware programs are deleted. After installing Bitdefender free version I reinstalled Spybot and Malwarebyte Anti-Malware. At first I seemed to generate lots of "virus" detections in Bitdefender each time I ran the malware and spyware programs. Then I updated Malwarebytes and the computer crashed. I restored the computer to a previous point and promptly uninstalled Malwarebytes and Spybot. My question is whether the use of malware and spyware programs is not allowed when using Bitdefender. Has anyone else seen these programs cause "virus" detections in Bitdefender.