Adding a 2nd party xxx.lib file to my uV3 (V3.30) project causes ERROR L218 NOT AN OBJECT FILE. xxx.lib was created on uV3 (V3.90), any ideas? Even when right-click on the .lib file, uV3 reports "Not a library file".
Not uncommon to get problems when linking a library built with a different version of the tools - especially if using c++.
Does it make a difference if you try to build a little library with your version of the compiler?
Have you asked Keil support?