OK , I worked out the problem . There is a conflict in the software or the old and new versions causing it to stop working. Here is how I fixed mine:
1. back up your MAXISYS to another storage device ( lap top or pc )
2. Carry out factory restore of the Android tablet (MAXISYS) ( it will wipe any stored info)
3. Update Android operating system if available
4. Set up wireless and ethernet connections on MAXISYS
5. Connect to Autel server and download latest operating system and manufacturers diagnostic updates (latest versions)
6. Exit out of Autel and carry out reboot of MAXISYS
7. Power up and check for operation .