# \[EXPECTED BEHAVIOUR\] License error due to MAC OS format
**URL:** https://forum.bfddrums.com/t/expected-behaviour-license-error-due-to-mac-os-format/1531
**Category:** Archive
**Created:** [September 28, 2021, 1:37pm UTC](https://forum.bfddrums.com/t/expected-behaviour-license-error-due-to-mac-os-format/1531 "2021-09-28T13:37:44Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@yong](https://forum.bfddrums.com/u/yong)
#### Post date: [September 28, 2021, 1:37pm UTC](https://forum.bfddrums.com/t/expected-behaviour-license-error-due-to-mac-os-format/1531/1 "2021-09-28T13:37:44Z")
Hello
After formatting the MAC OS, when I try to reinstall BFD, the following error appears.
☞Error : The serial has already been registered to a different account
What should I do?
Can I reset my serial number?
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### Author:  [@Steve63](https://forum.bfddrums.com/u/Steve63)
#### Post date: [September 28, 2021, 2:44pm UTC](https://forum.bfddrums.com/t/expected-behaviour-license-error-due-to-mac-os-format/1531/2 "2021-09-28T14:44:42Z")
You could try de-authorising it through the LM and then close and run the LM again?
It’s possible that it thinks you have (or you have) ran out of authorisations so if the above doesn’t work you should contact support at [support@bfddrums.com](mailto:support@bfddrums.com)
Steve
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### Author:  [@Rain](https://forum.bfddrums.com/u/Rain)
#### Post date: [September 28, 2021, 3:18pm UTC](https://forum.bfddrums.com/t/expected-behaviour-license-error-due-to-mac-os-format/1531/3 "2021-09-28T15:18:08Z")
Hi @yong
As @Steve63 has mentioned above, you may simply need to re-authorise, so to speak. contact support explaining the situation and they should be able to assist you further with that.