My feeling is that your problem has nothing to do with
multiple keys...
I would suggest to :
1) Check the section you are trying to extrude
2) Check the Part on which you are working. The error may
not be due to the extrude itselft but to previous errors.
3) Clean you part and model. Try to...
I am afraid you will have problems to define micron as length unit in I-DEAS. The important question is : what do you want to do ? Geometry modeling ? Simulation ?
The default global tolerance in I-DEAS is 0.01 mm or 10 microns ! If you wish to create dimensions of micron level you need to set...