I have not faced this problem. I would do the following. Search for all NEM-related files on your machine and delete them. Afterwards, install NEM again from scratch. Then it should usually work. Which WinOS do you use?
I think, I had the same problem!
You have to delete the file named 'accounts_cache_mainnet.json' and start NEM again.
I had this problem a serveral time, don't know why
You will find the file here: C:/Users/'youraccount'/nem/
cant log in into my xem wallet, the message says localhost 8989, and ncc is not runing, anyone can help?
I think, I had the same problem!
You have to delete the file named 'accounts_cache_mainnet.json' and start NEM again.
I had this problem a serveral time, don't know why
You will find the file here: C:/Users/'youraccount'/nem/