How to fix misaligned arrowheads in PowerPoint?

Question

I'm using a PowerPoint template ("Präsentation Biografie") found in the online templates of the PowerPoint app (PowerPoint 2019, MS Office Professional Plus). In the template, it seems that all lines and arrows are misaligned, i.e., the arrows are not centered with the lines and the lines seem to be aligned below the selection handles:

Even if I copy arrows from other presentations, they seem to become misaligned.

The question was already asked in the Microsoft forum, but no satisfying solution was given, the link to another solution is broken, and the thread is closed.

Answer 1

This post led me into the right direction: http://www.pptalchemy.co.uk/PowerPoint_Arrows.html

Detailed solution:

You may solve the issue:

• in the template (C:\Users\your_username\AppData\Roaming\Microsoft\Templates\name-of-the-template.potx) in which case you have to create a new presentation based on the template
• or using your presentation file (e.g., My Presentation v01.pptx) in which case you fix the error for your current presentation, but it will persist when you create a new presentation from this template → this is what I present here

How?

1. Save and close your presentation, make a backup of it.

2. Open the presentation in as a zip in a zip editor (e.g., 7zip – pptx files are basically zip archives).

3. Search for nStyleLst in all files of the template (e.g., using Notepad++ → Search in Files, select directory of the template)
   In my case, this was found in the file ppt\theme\theme1.xml
   

4. Check the align property of the <a:ln …> tag inside the <a:lnStyleLst> tag:
   If it is algn="in", change it to algn="ctr". This may occur multiple times in multiple files.
   Old:
   
   New:
   

5. Now that you edited all necessary files, zip the files back into, e.g., "My presentation v02.zip", then change the file ending back to "My presentation v02.pptx":
   

The arrows should look normal again: