I can login to the SAP B1 I just installed. However, it appears to have error 'You cannot open window [XXX] Purchase order with your current license' when I try to access the Purchase order tab. I checked that I can access the system without license for 31 days, does it mean that I can access the client but not the data?
do you have S-Account? if you are a customer then contact your support (SAP Partner and ask for the temp license.) to get the Hardware key, goto SAP Business One Service manager-- >> Select License Manager -->> Settings then the General Settings Window open... find the Hardware key in that window, copy the hardware key and send it to your SAP Partner.
anyway, you are still asking question, where your thread is marked as Answered. please marked it as question, otherwise other will expect that your thread is answered.
Will you please let me know from which Version and PL you upgraded your database to which Version and PL?
If you have Lifetime license and you have upgraded for same version but for higher PL then according to me you can still use the same license.......
If you have a 31 day license, you will just need to assign your user a license under Administration>License>License Administration.
If you have changed your hardware, you will need a new license file as the hardware key is part of your license. SAP should be able to provide you with a replacement license if you previously had a valid license, although to change to e new version / patch, you may need to make sure your maintenance contract is up to date, as this is what entitles you to the updates.
Check the SAP customer portal to see where you can apply for this, or contact SAP Support for assistance