On exporting archives only the last day is being exported although the filter "all" is used!
In addition on opening the archive MDI window or ETM the error " Archiv XX not completley read, set smaller timeframe"!
On exporting the archive data is written into a memory area with the size of 1 MB by default. This can be changed with the following project.ini entry

[ARCHIV]
SPEICHER=1000

1000 means: 1000kB so 1MB (default).
Set it to a higher value (try to fit your needs) an the error will be gone!

PS:
Since zenOn version 6.20 the default value is 1GB!