Merge Fields freezing in 2.8.1

[IcePlanet]

I'm very happy with Avidemux, but recently I see lot of freezes when processing interlaced content.

My Avidemux (2.8.1) is freezing when applying Merge Fields filter from Interlacing section. What I'm trying to accomplish is to convert from 50 FPS 1920x540 to 25 FPS 1920x1080.

The freeze occurs at end of first pass. Empty dialog box is thrown and Avidemux freezes.

Have found similar topic here but it seems as abandoned or resolved (depending what posts you look at).

Below is information about video file, py script and log file from Avidemux ending with:

[ADM_Composer::nextPictureInternal] 20:39:12-839 Next image PTS in ref is out of range: got 3951040000 us, wanted < 3951025378 us, discarding the image
[ADM_Composer::searchNextKeyFrameInRef] 20:39:12-839 Found nextkeyframe 3951780 1:5:51 at frame 197308
[ADM_Composer::nextPicture] 20:39:12-839 Cannot get next picture. Last segment
[ADM_videoFilterBridge::getNextFrameAs] 20:39:12-839 [Bridge] Base did not get an image
Saving crash file to C:\Users\Ice\AppData\Roaming\avidemux\crash.py
   ...   <Skipped some lines>   ...
Crash Dump for Assert failed :src->_height==_height at line 29, file F:\jenkins\workspace\VS2019_no_import\avidemux_core\ADM_coreImage\src\ADM_imageOperation.cpp

Have I done something wrong or is this bug?

Crash log of Avidemux: You cannot view this attachment.
Media info of file being processed: You cannot view this attachment.
Py script file of Avidemux (Filters applied in order "Merge Fields" - "DelogoHQ" - "Crop"): You cannot view this attachment. (zipped due to py not allowed to upload)

Edit: There are cuts done to the file, but cuts are done only on keyframes (with up and down arrows).