I ran into this the other day while building a SmarList Export Solution. The Document field length is 80 characters.In today’s network environments, it’s easy to get more than 80 characters in the file path. If you use the folder icon to pick the file name, it will allow you to pick a path name longer than 80 characters and then truncate it at 80. This means the everything will look right but the Export Solution won’t work.
There’s only one good solution and that’s to reduce the number of characters by moving or renaming the file.