@TIG Thanks to you, I was able to send him a message.

@Gábor
I erased the file and tried to activate it.
the results were the same.
What's PM? I am sorry that I am not good at English.

@Anton_S Of course. The file ending with ".scflicense" is correct. I deleted the file from my computer.
And I downloaded the attached file from the mail again.

The file was run by pressing the Validate License button but is not valid

@Anton_S I read the manual and followed it again. However, it continues to fail to validate the license it received by mail, an error message appears.
The contents of the error message are as follows.

msg_validation_error
Request to Sketchucation = ERROR_A04

1. I have installed the latest version of SketchUcationTools.
2. I registered for SketchUcation.

No matter how many times I try again, the result is the same. I want another solution. T_T..

win10 / clothworks v1.7.2 / sketchucation v3.1.8 / skechup 2019

Hi, I bought a license today.

But I can't register because there error.
(msg_validation_error Request to Sketchucation = ERROR_A04)

SCFLICenseSignature - Do not change or delete.
I deleted the above file and re-registered it. But it still doesn't apply.

I want you to give me a solution.

i'm sorry that i am not good at english.