When something goes wrong

Read the status bar first

It reports what just happened, and during a drag it reports what will happen if you let go. When an action seems to do nothing, it has usually already told you why.

The same goes for greyed out buttons and menu items. Hover one and it explains itself.

A button is greyed out

Hover it. The most common ones and their causes:

• Crossfade. The selected clip is not directly against a previous clip on the same video lane. Move them together, or the track is locked.
• Copy, Delete, Duplicate. Nothing is selected.
• Paste. Nothing has been copied yet.
• Play and the transport. There is nothing on the timeline.
• Zoom to Selection. Nothing is selected.
• Clear In and Out. No markers are set.
• Add Watermark. Add your video first.

I pressed Crossfade and nothing happened

Almost certainly it worked. The clips stay edge to edge and the blend straddles the join, so nothing moves on the timeline. Look at the diamond handle at the bottom left of the clip, which fills in when a transition is present, and read the status bar.

Playback stutters or reports dropped frames

Your machine cannot composite fast enough to keep up in real time. It is a preview problem and the export is unaffected. Lower the preview resolution.

A clip in a codec the preview engine cannot decode will also behave oddly while you edit and export correctly anyway. The Media Bin shows the codec.

Sound drifts away from picture over a long piece

Constant offset means something was placed in the wrong spot and you can slide it back. Offset that grows as the piece runs means the frame rates do not match, usually 23.976 material on a 24 timeline or the reverse. Sliding never fixes that. Check the frame rates in the Media Bin against the project frame rate in Properties.

The other cause is unlinked audio that was moved without its picture. Right click to relink.

A title is not showing

It is on a track below the footage. Video tracks stack and higher ones cover lower ones. Move it up with the track header's Move Up.

Text is unreadable on the platform but fine in the preview

It is in the region the platform's interface covers. On vertical feeds the bottom fifth carries the caption, account name and buttons, and the right edge carries the like and share column. Turn on Safe Zones with the platform preset selected and move the text inside the box.

The other cause is a thin font. Compression treats a one pixel stroke as noise and smooths it away. Use a heavier weight.

Media has gone missing

Source files were moved, renamed or unplugged. The project holds references, not footage. Put the files back under their original names and paths and reopen the project.

The export looks washed out or crushed compared with the edit

Almost always a levels mismatch, where black is being read as 16 instead of 0 or the reverse. It shows as a uniform lift or crush rather than a colour shift. See Why your export looks different from your edit.

The export will not fit the size limit

Size is bitrate times duration. Turn on Target file size in the export dialog's Advanced section, and if that still cannot reach it, shorten the piece or drop to a smaller platform preset. No encoder setting beats the arithmetic.

A platform preset warns about duration

Several have a maximum length. Set an In to Out range covering the part you want, and choose that range in the export dialog's What field.

An export failed

The queue row carries the error. Common causes are no write permission in the output folder, a filename already in use, and a source that went missing partway through.

I lost work

Look in data\autosaves beside the executable. The most recent ten are kept, a couple of minutes apart.

Windows blocked the program

It is not code signed. Choose More info, then Run anyway. Compare the download against the SHA-256 on the download page if you want to confirm the file first: certutil -hashfile AVPrep3-portable-0.1.0.zip SHA256.

Nothing saves, or presets vanish between sessions

The program folder is somewhere Windows will not let it write, which is usually Program Files. Move the whole folder somewhere you own, such as your desktop or a second drive.