I have a serious problem with playing a very large map in Heroes V ToE. The map is called "The Great Canyon" (downloaded from http://www.maps4heroes.com) and is huge in size (1,1 MB). It does play well, however after some time saving and loading becomes difficult. What happens at first is that in-game loading becomes impossible, i.e. while playing you cannot reload, you have to quit and restart the game first. Second, loading some saved versions of the game cannot be loaded altogether, which means that I have to revert to an older save version and loose some progress. Third, while saving I notice that different saves get the same name! This happens e.g. yo "Autosave 1". I have a screen save at my disposal.
Note: this does not happen on any other map/campaign as yet.