I have tried ever editor there is and none of them work right. Sometimes I can get it to work but most of the time it will not allow me to edit anything. Of those times I can use the editor half the time it will not save the data.
I have went through all my extensions looking for a possible culprit and nothing stands out. This only started happening after the last update.
Another strange thing is when i can edit the content. I can see the other messages I have created. Otherwise if it is not working all the messages are blank.
Make sure you are using the lastet version of JCE and only install the plugins you really need. I am notorious for installing everything I have for a given extension.
After I uninstalled JCE and then reinstalled it with the above parameters (in fact try it without installing any plugins first). I solved all my issues and can confirm that this in fact is not a DT Register issue. If you have any time with Joomla you already know that Tiny MCE is totally worthless and should not even be used. I am sure you do or you would not have listed it as an option.
You can also install the Editor Switcher found in JED which allows you to instantly switch between editors on the fly inside of an article. I have added the link for you here.