after update to Plasma 6, krusader (2.8.1) internal viewer lost its ability to recognize mime-types. It does not highlight text inline with file extension, when attempting to open image file it opens ASCII-text instead… when running from command line there is the warning output: kf.service.services unknown@0 # KMimeTypeTrader: MIME type “all/allfiles” not found. Purging/Reinstalling krusader did not solve the problem. on plasma 5 all worked fine. Any ideas how it can be fixed?
kdeneon user edition
added bug report: 485225 – Krusader issue with mime types after P6 update
interestingly enough that it does not work on all new post-P6-update kdeneon setups. But on the one of my kdeneon-systems that was updated to P6, internal viewer works as intended…
There is one more thing (maybe smoking gun), when starting krusader for the first time after fresh install there is Dialog saying about Missing Plugin, namely it says
No text editor plugin available
Internal editor will not work without this.
You can fix this by installing Kate
installing Kate does not solve the problem. F3 opens all in plain-text mode, images, cpp, xml, … everything.
when pressing F4 (invoking internal editor) it just does not work! and show the same Dialog about Missing Plugin. So, it look like that something wrong with internal editor. Maybe it is missing as dialog says? but why is that? and how can I fix it? make it work?
update:
i found the way how to make internal editor to work partially, you need to install following packages:
ktexteditor-data 5.115.0-0xneon+22.04+jammy+release+build53 all provide advanced plain text editing services
ktexteditor-katepart 5.115.0-0xneon+22.04+jammy+release+build53 amd64 provide advanced plain text editing services
then F4 starts to open all text files with highlighting!.. and console error about mime (see early posts) disappears and Missing Plugin Dialog is also gone!
Unfortunately, image files still can’t be open with F3, it results in plain-text… probably, some kde-package also needs to be installed for this to work, but I can’t figure out which one…
I found one kdeneon system where Krusader’s F3 with images was working. After some digging and pockets comparison I finally found that libkf5khtml-bin package is making difference. Once it is installed then Krusader’s Internal Editor (F3) again starts to open images! Hallelujah!
unfortunately there is no standard buttons like Fit Image, and when you resize window image does not scale 
Checked with latest 2.9.0-dev, its internal editor is also missing a scaling functionality on Toolbar, and it also does not scale down when resizing window. So, I start to think that most like this is also due to some missed library… the question is only which one? any ideas?
