High-Resolution Mosaic Not Generating or Not Compiling Properly

Updated 2 weeks ago · 3 min readIntermediate

If Export Hi-Res on the PMWall Runtime tab fails or appears to do nothing, PMWall is almost always telling you that the mosaic or its tiles are not ready. This article covers the messages you may see and how to clear them.

For the normal export workflow, see Exporting the Final PMWall Mosaic.

Where the Export Is Saved

The export is written to the Prints folder inside the event folder:

C:\PMWall\Events\{Event Name}\Prints\

The file is a single LZW-compressed TIFF named like:

mosaic_master_20260818_143005_50x50_600x600.tif

The name records the timestamp, the grid, and the tile size. Click Open output folder on the Runtime tab to go straight there.

Tip: The export is one merged TIFF, not a set of tiles. If you are looking for separate tile images, those are the individual files in the event's final folder, which is a different thing.

"The mosaic is not complete yet."

PMWall exports a print master only from a completely filled wall, because every cell has to contribute a tile to the merged image.

Check Cells Left under Event Timer on the Runtime tab. If it is above zero, the wall still has empty cells. Either keep the event running until it fills, or add more photos to the event.

"The final mosaic tiles are incomplete. Missing {column}_{row}.jpg."

A tile file that the placement data expects is not on disk. This usually means the final folder was edited by hand, or files were removed while the mosaic was running.

Do not delete anything from the event's final folder during or after an event you still intend to export. If tiles were removed, the reliable fix is to restart the mosaic and let PMWall re-place the affected cells.

"All final tiles must match size {w}x{h}."

Every tile in the export has to be the same pixel size. Tiles end up mismatched when Cell output size changed partway through an event -- typically because a template with a different value was synced onto an event that already had wall progress.

This is exactly what the destructive-change confirmation warns about when you sync. Settle Columns, Rows, and Cell output size before the event starts. To recover, clear the event artifacts and run the wall again on one consistent grid.

"The runtime placement data is incomplete."

The placement record has duplicate or missing cell entries. Restart the mosaic so PMWall rebuilds its placement state from the tiles on disk, then export again.

The Export Takes a Long Time

This is normal on large walls. The export merges every tile into one master image, so the work scales with the grid and the tile size.

A 50x50 grid at a 600 px Cell output size produces a 30,000 x 30,000 pixel master. Expect large grids to take time and to need free disk space on the event drive. Let it finish rather than closing PMWall partway through.

To keep the master smaller, lower Cell output size in the Cloud template before the event. At 300 DPI, 600 px is a 2 x 2 inch printed tile.

Still Not Working

Confirm the wall is genuinely full and every cell shows a tile in Mosaic Preview.
Confirm there is enough free disk space for the merged file.
Confirm the event folder is on a local drive, not a network or removable one.
Restart PMWall and export again.
If it still fails, collect the logs from Settings > Storage > Open Logs and contact Foto Master support.