When we try to process a job through the ATP when we
“Process Parts List” and you get a dialog box appearing that says “Could not
covert variant type (Null) into type (String)”
This has occurred because the ‘Label Format Name’ has
no value.
(Bypass: if you turned off “Create label output” then this would not
prevent you nesting the job, but you will not get labels.)
The problem is located in the
LabelFormatCollection.lfc.
- Location: example “C:\AllMasterSoftware\EzyNest5\AutoTP\Labels”
Fix:
One
method for this would be to import the LabelFormatCollection.lfc from a backup,
as the current file will not necessarily be correct for all the data of label
positions and quantity.
Another
method is to use the LabelMaker.exe to reconfigure the correct settings
required for the Label Format.
Origin: Whilst this is not confirmed, it is theorized that if the customer is multiple
selecting *.ljd and printing them all at once, or trying to print them too fast
together, then the application LabelMaker.exe (which writes the LFC during
close) is failing to write the file correctly when it shuts down and commences
the next label.

TIP: Click the attachment to download this HowTo to your desktop as a .pdf