# Failed to process at step 3 ”Merge orthomosaic tiles failed”

**URL:** <https://community.pix4d.com/t/failed-to-process-at-step-3-merge-orthomosaic-tiles-failed/34005>\
**Category:** PIX4Dmapper Questions/Troubleshooting\
**Created:** [August 14, 2025, 11:04am UTC](https://community.pix4d.com/t/failed-to-process-at-step-3-merge-orthomosaic-tiles-failed/34005 "2025-08-14T11:04:21Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![henrique.dickel](https://avatars.discourse-cdn.com/v4/letter/h/e99b99/32.png) [@henrique.dickel](https://community.pix4d.com/u/henrique.dickel)\
**Post date:** [August 14, 2025, 11:04am UTC](https://community.pix4d.com/t/failed-to-process-at-step-3-merge-orthomosaic-tiles-failed/34005/1 "2025-08-14T11:04:21Z")

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Hello, everyone!  
Lately I am having this problem when processing orthomosaics with bigger quantity of photos, when Step 3 is executing the ‘Merge Tiles’, this error occurs.

 ![image](https://global.discourse-cdn.com/pix4d/original/2X/b/bdb9ee5154aea65039d25253bbc2cec5235c7d16.png)

Besides this error, I’m also noticing some slower processing time, but I personally didn’t change any configuration on the machine that runs Pix4D Mapper.  
Some informations to help the diagnose:

- There is around 700 GB of free disk space in the D:;
- The images are also saved in a local disk;
- Pix4D version: 4.8.4

I will send in annex the log and quality report. If someone already encoutered this problem and know a solution, please share!

Best regards  
[TESTE\_WINGTRA\_2025\_08\_05\_report.pdf](https://community.pix4d.com/uploads/short-url/nR2QinQBuHckIU5s0hAh8cOrs1q.pdf) (1.5 MB)  
[LOG\_WINGTRA.txt](https://community.pix4d.com/uploads/short-url/iS3GLbZXyNd6cj1l7nEiqr760t1.txt) (44.4 KB)

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<div class="post-metadata">

**Author:** ![Kapil\_Khanal](https://sea2.discourse-cdn.com/pix4d/user_avatar/community.pix4d.com/kapil_khanal/32/304_2.png) [@Kapil\_Khanal](https://community.pix4d.com/u/Kapil_Khanal)\
**Post date:** [August 14, 2025, 5:13pm UTC](https://community.pix4d.com/t/failed-to-process-at-step-3-merge-orthomosaic-tiles-failed/34005/2 "2025-08-14T17:13:10Z")

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Hello @henrique.dickel, Is the processed result opened on other software? I would suggest you to close all the software and reopen PIX4Dmapper, rerun step 3 and see if that resolves your issue?  
If you still have issue, send us the full logfile so that I can look into it.

> **[How to export the quality report and log file -PIX4Dmapper](https://support.pix4d.com/hc/how-to-access-the-quality-report-and-logfile-pix4dmapper)**
>
> This article explains how to access the quality report and log files from PIX4Dmapper.