The root cause of the problem that custom objects are prohibited from being deserialized. See more at stackoverflow answer:aem - Sling job not being processed with custom serializable property - Stack Overflow

I have the same issue, restart haven't help me. AEM 6.4.3

Hello Jörg,Yes I was verifying that files are cashed before I request it, but only 503 was returning content from cache.When I was requesting resource with 502 and 504, cache was deleted and 502/504 status was returned on dispacherThank you,Yaraslau

We use query manager, because generated query is much more bigger. I just show part of it

As I noticed. Preppocessor triggered on delete only for activated pages. This behaviour is ok for me.

I configured Custom Workflow via Workflow Launcher Configuration on 'removed' Event type. Result the same as for first case.Workflow executed after page has been deleted.

Hi,Thanks a lot.Yaraslau

Seems like dispatcher returns wrong css file, and chaches normal variant. 

Libs were on publish, but something was corrupted or similar. I just reinstalled it

You was right. I have installed package with /libs/cq/ui/ content from author and it's ok now. Thanks