Syntax and variables not defined.

[miks]

I wonder why it always says this things every time I build my scripts. But it all working. Thanks in advance.

[GreenSock]

Very difficult to troubleshoot blind but it sounds like maybe your environment isn't set up to recognize globals or maybe you're not importing things properly? If you're still having trouble, please provide more details about the environment and [ideally] give us a reduced test case that we can run on our end to see the errors. 

[miks]

I am using JointsWP as my based to create my website. I think it only happens when the npm is already compiling all the codes? Thanks!

[GreenSock]

Sorry, I have no idea what JointsWP is, so that doesn't help much. NPM doesn't really "compile" code so I'm not quite sure what you mean. GSAP is indeed available via NPM though. Do you have a reduced test case that we can look at maybe?