Nextcloud PHP (i think) problem

I have a problem with my Nextcloud server. I installed it via snap packages and the strange thing i that first 1-2 days i don’t have any problems… I hope that someone can help me :slight_smile:

Nextcloud version11.0.5 (stable):
Operating system and version Ubuntu 16.04 LTS:
Apache or nginx version don know how to check the version:
PHP version7.0.23:
Is this the first time you’ve seen this error?:
Can you reliably replicate it? (If so, please outline steps):

I have several problems:
1 -> Last cron job execution: 2 hours ago. Something seems wrong.
2 -> Allowed memory size of 134217728 bytes exhausted (tried to allocate 24576 bytes) at /snap/nextcloud/3680/htdocs/lib/private/legacy/image.php#538
3 -> The “Strict-Transport-Security” HTTP header is not configured to at least “15552000” seconds. For enhanced security we recommend enabling HSTS as described in our security tips.

The output of your Nextcloud log in Admin > Logging:

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):
How to get it ?

The output of your Apache/nginx/system log in /var/log/____:
How to get it ?