I have this same error. I tried optimizing my attachment....renaming my attachment to a smaller version, etc. Also hard install, and various other attempts to fix. I've efiled many other returns that had much larger attachments. Ultimately, I called Lacerte. They told me that they ARE aware of this issue, and have been working on it all through March and still now! They took my info, and are supposed to email a message when the error has been resolved. Very frustrating....but you can call them to get on their email list.   

Just an FYI for anyone else with this issue...... Just got off the phone with Lacerte support. They are aware of this issue, and are working on it. Apparently, have been working on it for all of March! It is not necessarily related to the attachment..... at this point they have no other information.  

Ok. I don't like it, lol.....but I will go with it. (I am supplying my Form to the Seller (to use my language in the Employment Contract and Non Compete section....so I think I will just change it (or just blank it out) on the one I provide to him. I'm afraid MY dentist is not going to like it! ha)   Thanks for your reply.