The message “You entered an invalid key” will be displayed only when an invalid key is entered in the edit box.
The Syncfusion Essential Studio unlock key is version specific. Please make sure that you are entering the corresponding key for the version you are trying to install.
When copying a key, make sure that extra space has not been added to the end of the key or missing @ or = symbols in prefix and suffix of the key respectively.
Regards,
Rachel Gomez