Hi Tatyana,

Allow me to first give you some nice introduction, to give you the big picture and streamline terminology: ViewTXS 2020 Day 2: Integrating New Publishing Outputs SDL Tridion Docs 

I assume you attempted to dig deeper in the Web Client > Event Log screens. To see the details per event line, and by pressing the paper clip icon you can even see (part of) the DITA-OT logging. Which looks to be your culprit.

In case this does not work out, a classic approach on debugging is

1. Settings > OutputFormat ... edit the properties of the OutputFormat and Disable the "Clean up" flag. This means that after version/resolution calculations all files will be left on the publish server under C:\InfoShare\DataDITA\Publish\Data
2. Publish your problematic publication
3. (Remember to Enable the "Clean up" flag again or you will run out of disk space because all intermediate publish files will eat the disk space)
4. The intermediate folder contains some goodies for you
   1. C:\InfoShare\DataDITA\Publish\Data\nv25izltan4\work\logs\ditaot.log contains your logging
   2. C:\InfoShare\DataDITA\Publish\Data\nv25izltan4\__RunPublishPlugins.cmd allows you to re-run the postprocess plugins (where DITA-OT is one of those) again in console mode
   3. Have a look what happens on the file system, have a look in Process Explorer, etc.... debug

Best wishes,
Dave