This is not realy an error. This message inform you that the readed section 94.0 x 43.6mm is not defined in your material standard sections.
Here it more a drawing mistake. Because if you mesure the part it doesn’t have 44.0mm thickness but 43.6mm.
As @DaveR says, you need to change unit precision to see the true dimension.
Else, if the dimension is correct, just hit the “+” button to and the current section to your material definitions. And the warning but will disappear !
Does it happen inCutList 4.1 as well?
@DaveR is CutList realy better than OpenCutList to read dimensions … ?