SCC files created in Premiere have timing/packet errors in other programs (new issue as of 2026)

Premiere is exporting syntactically valid SCC text, but the SCC events are packet-overlapping by 1–5 frames in many locations, making the file unusable in MacCaption and Subtitle Edit.

This was not an issue before 2026 Premiere and does not show up in 2025 Premiere, and even resolves if I export from 2025 Premiere the SCC files that 2026 Premiere creates, but it’s a massive problem to have to do that for every SCC file I create in 2026 Premiere.

The problem is this: when creating SCC files (NDF) from 2026 Premiere, they now have overlapping timing errors when opened in other programs such as MacCaption or Switch. This is leading to rejections of SCC files we are creating and supplying to our clients. The problem is also undetectable within Premiere because the files will import and display normally within premiere. 

This file is not “corrupt” at the raw text/hex/parity level, but it does appear to be invalid or noncompliant SCC because the SCC command packets are timed too tightly together. That explains why Premiere can open it but MacCaption and Subtitle Edit reject or choke on it.

What MacCaption is flagging is not bad hex. It is saying: “This SCC row starts at a timecode, but the SCC data on that row takes a certain number of frames to transmit. Before that transmission finishes, the next SCC row starts.”