Error 18 (Old Serial Number Incorrect) during AutoCAD 2015 Activation

[NEHA2895]

Hello All,

After installing the 2015 Autodesk AutoCAD LT program, when I try to open it, the "Product Registration & Activation" page opens up, asking for the old Serial Number. This 2015 version is a one-seat, Standalone license. Our previous 2010 license was also the same. When I enter the serial number of the 2010 license, it says that the serial number you entered is not valid, and it is Error code # 18.

Please advise.

Thank You,

Neha

[jessica.t]

Hi Neha and welcome to the Autodesk Community!

I looked up your license information using your email address and found that you were able to activate your AutoCAD LT 2015 this morning. If you have any further questions please let us know.

For other users, invalid serial number errors tend to pop up when a license has already been upgraded or returned and is no longer available for automatic activation or use.

Please see this Autodesk Solution on further causes of the invalid serial number error. Thanks!

[NEHA2895]

Hi Jessica,

Thanks very much for the quick response! It does seem to be functioning properly, now. AutoCAD 2015 opened after I received the email from AutoDesk. However, they gave me an Activation code in the email, but when I opened CAD, it did not prompt me to that screen where it normally asked before for the old serial number. Since it is working okay now, I'm assuming all is good. I hope no other issues come up later, though.

-Neha

[jessica.t]

Hi Neha!

I'm glad to see that you're up and running! You likely did not see that messaging again as the Activation and Registration manually created the relationship between your 2010 and the new license so that you could seamlessly activate.

Please be sure to let us know if you need anything else at all. Thanks!