Support intro
Sorry to hear youâre facing problems 
help.nextcloud.com is for home/non-enterprise users. If youâre running a business, paid support can be accessed via portal.nextcloud.com where we can ensure your business keeps running smoothly.
In order to help you as quickly as possible, before clicking Create Topic please provide as much of the below as you can. Feel free to use a pastebin service for logs, otherwise either indent short log examples with four spaces:
example
Or for longer, use three backticks above and below the code snippet:
longer
example
here
Some or all of the below information will be requested if it isnât supplied; for fastest response please provide as much as you can 
Nextcloud version (eg, 12.0.2): 16.0.3
Operating system and version (eg, Ubuntu 17.04): Ubuntu 18.04 LTS
Apache or nginx version (eg, Apache 2.4.25): Apache
PHP version (eg, 7.1): 7.2
The issue you are facing:
problem with formulas. I want to import data from another spreadsheet, itâs possible?
Is this the first time youâve seen this error? (Y/N): y
The output of your Nextcloud log in Admin > Logging:
Error PHP filesize(): stat failed for /mnt/ncdata/parkeszak/files_versions/test/abc.xlsx.v1563732989 at /var/www/nextcloud/lib/private/Files/Storage/Local.php#169 2019-07-21T20:45:02+0200