Ok, it is now no more Errors, but Warnings only by compile. However I found now any of my single EA in my Expert Advisors will caused the platform freeze right after attaching, although it shown that it was Loaded Successfully. I have to use Task Manager to End Task it in order to restart MT4. Any advise on this issue?The error text suggests that the files from the Include folder in the zip archive weren't copied to the MQL4\Include\ folder of your MT4. You just need to copy those three folders (Experts, Files, and Include) to your MQL4 folder - it will put all the files where they should be.