idesign file keeps closing coming up with a message saying "The network connection was lost for the file Nicholas Daley Research File .indd, or the file was modified by another process." and then "Error: Adobe inDesign is shutting down. A serious error was detected. Please restart inDesign to recover work in any unsaved inDesign documents"
It then closes down then when I try and open it, it says "InDesign could not open your file because it has been created in a newer version - Adobe indesign 18.1. You can convert and open the file but you may lose out on content created using the features specific to the latest versions. for the best experience, we recommend you updating indesign to the latest version."
when i try converting it, it gets to 33% then stops working. When using indesign before it was getting really slow and lagging, i made sure everything was linked up etc, and then updated it because it told me to, it let me continue working then now i keep getting this message. Every so often i can get access to opening the file again but then after a couple pages same thing happens again.