Also having lots of problems with ACF PRO 5.0.x and WPML 3.1.6
Something seems to be fundamentally broken. I tried a lot of things, hacked the ACF and WPML files to generate debug-output etc. but I can’t track down the real problem. Behaviour seems to change even with activation order of ACF and WPML plugins and/or other weird requirements.
Some fields are obviously not saved if they do not exist in corresponding translated fieldgroup (weird), at the moment a simple field in a 1-field fieldgroup can not be changed any more, etc.
From reading the WPML support forum it seems that they try to sell their “Types” plugin [#1, #2, #3, ..] as a working alternative instead of support.
As I already bought ACF PRO 5 for a customer, I would really like to use it, invested a lot of time already, but probably now have to look at “Types” as well. 🙁
