[CIUv3] Custom Installer Ultimate v3

[Cesar82]

After testing the conversion of @Prettyboy099 I found a bug when switching to the installer finish page.
Displays an error when not add the Close button in the installer and going to the finish page.
To fix this, do the following... Open the CIU 3.0.0.1.b6 script and search for:

CstmBtn[BtnI(CloseBtn)].ClickAction := @NextBtnClick;

Insert the line highlighted in red.

CstmBtn[BtnI(NextBtn)].ClickAction := @NextBtnClick;
if BtnI(CloseBtn) >= 0 then
  CstmBtn[BtnI(CloseBtn)].ClickAction := @NextBtnClick;

If other errors arise I share an HF.
Thanks @Prettyboy099 for using CIU 3.0.0.1.b6, thanks to him this bug will no longer be present in next version.