Attachment size limit => increase to at least 2MB

[yemo]

williammiller

With the longer campaigns, more designs accumulate in the savegame over time.

Even after deleting bmp pictures and the autosave files and using 7z, the 1MB limit is just not enough anymore to reliably be able to upload savegames in later stages of the campaign.

[williammiller]

I have just changed attachment size limit to 3 Mb, which is the largest it can go.