Did you have a chance to review ACS Common error handler?It might a good start for your own project: Error Page Handler

It has nothing to do with jcr:mixinType. As per a Query Explanation, your query should be served by oak:index/lucene:/libs/granite/operations/content/diagnosistools/queryPerformance.htmlTry to employ checkConsistency MBean to verify that /oak:index/lucene is valid/system/console/jmx/org.apache.jackr...

When you determine the latest good revision, you can find the approximate date and time of that revision:Offline Compaction fails with SegmentNotFoundException & IllegalArgumentException step 4.Next, you can query your JCR by date of creation and modification. For example, for cq:Pages you can use a...

In AEM 6.5 you will have a mix of cloud services configurations. Those that still resides under /etc will be shown in TouchUI as "Legacy Cloud Services"For ACS-Common Tool you might need to re-install 6.5 compatible release.

With that workflow step, you are trying to update jcr:content/metadata/ds:validFrom. "ds:validFrom" is not an OOTB metadata property.You need to register "ds" namespace via: /crx/explorer/index.jsp -> Node Type Administration -> Namepsaces -> New

This type of installation is not officially supported and has never been QA

There is nothing wrong with creating multiple templates, the number of templates should be driven by your business requirements.Have you seeing WKND project: Getting Started with AEM Sites Chapter 2 - Creating a Base Page and Template  In chapter 2 it covers two templates creation

It looks like you are trying to make a join search for title "cost" OR description "cost" from a page under path=/content/some-pathi.e. the XPath query should be something like:/jcr:root/content/some-path//element(*, cq:Page)[(jcr:contains(jcr:content/@jcr:title, '*cost*')or jcr:contains(jcr:content...

Asset metadata should be extracted and stored under /content/dam/folder/file.psd/jcr:content/metadata and hence you can query those properties.If the value that you are looking for is backed into file's metadata AEM will extract it. I uploaded some sample PSD files into a DAM and I did not find a DP...

The best practice is to have no more than 1000 child objects.