If you are seeing the -25001"Serial not found" error message when activating, it simply means you typed the Serial wrong.
The most common mistake is to confuse the letter "O" with the number "0". Other common mistakes are not respecting upper/lower case, not inserting Hyphens, or inserting the correct Serial, but with another product selected for activation, which will of course not work, even if the serial is correct. You will not see a -25001 Serial Not found error in this case, but a message saying "This doesn't seem to be a correct serial for xxxxx", meaning you selected the wrong product to activate.
Another common mistake, are inserting something else entirely as the serial, like the order number or the SKU number. You have to insert the SERIAL Number. The Serial Number is indicated on your purchase receipt as "Serial Number".
