Both .logicx and .logic files are projects from different versions of Apple Logic Pro software. We couldn't reliably verify if it's possible to convert logicx to logic or vice versa, however it seems that it is only possible to produce a newer versions from older and not the opposite and as such logicx to logic conversion seems unlikely.
This conversion entry was verified by us and conversion was flagged as wrong or not possible.
Usually this happens when the conversion would try to convert different types of data between each other, such as audio to image, or it is not possible because incompatibility between programs, caused by closed file formats, very limited support etc.
If you find entry that you feel is flagged as bad wrongly, please tell us in the discussion below with as much as information as possible so we can fix it.