I cannot import .enex files.

[Tomoko.M 0]

I exported some notebooks from an account and imported them another account by .enex files.

When I have finished import a file, I could open imported notes. However, few minutes later, the notes disappeared from the notebook. (Only the notebook was left with no contents.)
Is this error of the app? 

• I use Evernote for Mac (10.36.4). 
• I am a free member.
• I tried some .enex files and they were all under 60MB.

[PinkElephant 8,068]

The 60 MB is your total allowed upload for 30 days. If you imported several ENEX files, it may well be you have exhausted your complete upload volume already.

You can check in account information if you have an available upload volume left.