I've been using KDL for quite a while for 1080P output from OBS with no issues.

Now I just want to create simple 20 second videos for IG. I've got project format set to 1080x1080 29.97fps under custom.
It renders with the error below, but plays on my desktop (Win 10 + KDL Version 22.04.0) just fine.

But when I try to upload to IG, FB or LI, I get an error. On LI I get: "This video is corrupted. Try a different file."

Any help is greatly appreciated. I'm rendering at 50% quality.
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I am getting this render error:
Rendering of D:/Videos/Linked in/Grant Covers/3-Wednesday/Instagram elements/IG Posts/IG-5-16l.mp4 crashed

x265 [info]: HEVC encoder version 3.4 x265 [info]: build info [Windows][GCC 8.1.0][64 bit] 8bit x265 [info]: using cpu capabilities: MMX2 SSE2Fast LZCNT SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2 x265 [info]: Main profile, Level-4 (Main tier) x265 [info]: Thread pool created using 8 threads x265 [info]: Slices : 1 x265 [info]: frame threads / pool features : 3 / wpp(17 rows) x265 [info]: Coding QT: max CU size, min CU size : 64 / 8 x265 [info]: Residual QT: max TU size, max depth : 32 / 1 inter / 1 intra x265 [info]: ME / range / subpel / merge : hex / 57 / 2 / 2 x265 [info]: Keyframe min / max / scenecut / bias : 25 / 250 / 40 / 5.00 x265 [info]: Lookahead / bframes / badapt : 15 / 4 / 0 x265 [info]: b-pyramid / weightp / weightb : 1 / 1 / 0 x265 [info]: References / ref-limit cu / depth : 2 / on / on x265 [info]: AQ: mode / str / qg-size / cu-tree : 2 / 1.0 / 32 / 1 x265 [info]: Rate Control / qCompress : CRF-30.0 / 0.60 x265 [info]: tools: rd=2 psy-rd=2.00 early-skip rskip mode=1 signhide tmvp x265 [info]: tools: fast-intra strong-intra-smoothing lslices=6 deblock sao
[mp4 @ 00000000070f6300] Timestamps are unset in a packet for stream 1. This is deprecated and will stop working in the future. Fix your code to set the timestamps properly [mp4 @ 00000000070f6300] Encoder did not produce proper pts, making some up. [mp4 @ 00000000070f6300] Application provided invalid, non monotonically increasing dts to muxer in stream 1: 957440 >= 957440
x265 [info]: frame I: 3, Avg QP:28.92 kb/s: 4967.19 x265 [info]: frame P: 118, Avg QP:35.87 kb/s: 72.66 x265 [info]: frame B: 477, Avg QP:37.75 kb/s: 26.82 x265 [info]: Weighted P-Frames: Y:0.0% UV:0.0% x265 [info]: consecutive B-frames: 0.8% 0.8% 0.0% 0.0% 98.3% encoded 598 frames in 18.26s (32.75 fps), 60.65 kb/s, Avg QP:37.33

Does the rendered video play in VLC? If yes then it’s something wrong, maybe with the upload.

With the version 22.04 Kdenlive detects clips which are not effect “friendly” and converts them. Maybe it helps to convert the clips used in the timeline to a user-friendly format and render again. I think you can right click the clip either in the timeline or in the project bin and chose “convert to a user-friendly format” or similar.

Thanks
Yes, it plays in VLC
Simple static graphic and then text using typewriter effect. That's all it is.
This is the third time I've done it from scratch.
Will not upload.

if there is a rendering error the output file is corrupted and correctly any uploading service will not process it. (VLC play it because the missing end of the file is not an issue for a local execution)... but probably on a server with tons of other videoclips from all the world a "corrupted/strange" uploaded file can be a RISK... (code injection, code append?, what else?)

you can try to postprocess the 1080x1080 file using FFMPEG .. or "convert" using the VLC (not the app for W10/W11 but the application from videolan site)

the conversion will "close" correclty the video file.