After 7 days – problem is solved and fixed!
After I upgraded Windows 7 to Windows 10 I started to use Metatrader. I created expert advisor EA, and after compiling I got : “ex4 write error”.
After that I tried to compile a lot of indicators and EAs and all of them showed the same – ex4 write error.
What this means :
1) Your disk is full and you can not write files. (in my case I have 10GB free.)
2) Folder permission doesn’t allow writing. (in my case everything is fine)
If you see that MQL4 folder allow for system and administrator to write files this is not problem.You can check this if you press in Metatrader (mt4) : File/Open File Folder and than in MQL4 folder you press Properties than go to Security /Advanced and see write permissions.
3) Metaeditor has bug. (This is problem in my case)
On Novemeber 12, Metatrader got new version. 4.00 Build 910. In this version Metaeditor has problem to write compiled files. It will be fixed in next days but meanwhile you need to fix problem.
Copy metaeditor.exe file from older version to new version. This is all !!!
In attach you can download version which I use. This is only metaeditor.exe file which you need to copy in installation folder.
Please check new versions of mt4 and mt5 and check article about mt4 vs mt5.