cache problems

Hi Forum!

I have cache troubles on my multilanguage modx 2.5.7 page with several contexts (runnung in php7.1 latest). The pages work fine but after a while it shows only the homepage of the main context. After deleting the cache everything works fine again. I dont know what do to.

The error log shows:

[2018-03-05 21:39:41] (ERROR @ /files/core/cache/includes/elements/modplugin/7.include.cache.php : 83) [Babel] Could not load menu for context key: "slowenia". Try to check "babel.contextKeys" in System Settings. If this is intended, you can ignore this warning.
[2018-03-05 21:40:12] (ERROR @ /files/core/model/modx/modcachemanager.class.php : 394) Error caching action map mgr/actions
[2018-03-05 21:40:43] (ERROR @ /files/core/model/modx/filters/modoutputfilter.class.php : 443) PHP warning: A non-numeric value encountered
[2018-03-05 19:58:40] (ERROR @ /files/core/model/modx/modcachemanager.class.php : 509) Error caching script elements/modplugin/3
[2018-03-05 19:49:30] (ERROR @ /files/core/model/modx/modcachemanager.class.php : 394) Error caching action map mgr/actions
[2018-03-05 19:49:30] (ERROR @ /files/core/model/modx/modcachemanager.class.php : 344) Error caching lexicon topic lexicon/slo/core/default

What can I do? Does anyone know?

There may be some relevant information in this thread.

https://forums.modx.com/thread/87338/one-more-time-the-infamous-cache-errors-break-my-manager-problem

On a side note make sure you upgrade your MODX.

Thanks guys,

What Ive done so far:
Update to modx 2.6.1, deactivated memcache, deactivate caching lexicon topics.
I will investigate if problems still come.

The "cache clear"-Plugin used on the mainpage seems to be a brutal chance to solve the problem at least

Does anybody know if i need that: Is there a chance to oppress the cache-clearing messages which come out of the plugin by using it?