diff -r 73a87b1aacc2 -r d9208a660094 src/jdk.compiler/share/classes/com/sun/tools/javac/processing/JavacProcessingEnvironment.java
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/processing/JavacProcessingEnvironment.java	Wed Apr 17 01:21:56 2019 -0700
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/processing/JavacProcessingEnvironment.java	Tue Apr 30 10:39:22 2019 +0200
@@ -444,7 +444,14 @@
             } catch(ServiceConfigurationError sce) {
                 log.error(Errors.ProcBadConfigFile(sce.getLocalizedMessage()));
                 throw new Abort(sce);
+            } catch (UnsupportedClassVersionError ucve) {
+                log.error(Errors.ProcCantLoadClass(ucve.getLocalizedMessage()));
+                throw new Abort(ucve);
+            } catch (ClassFormatError cfe) {
+                log.error(Errors.ProcCantLoadClass(cfe.getLocalizedMessage()));
+                throw new Abort(cfe);
             } catch (Throwable t) {
+                log.error(Errors.ProcBadConfigFile(t.getLocalizedMessage()));
                 throw new Abort(t);
             }
         }
@@ -461,6 +468,7 @@
                 log.error(Errors.ProcBadConfigFile(sce.getLocalizedMessage()));
                 throw new Abort(sce);
             } catch (Throwable t) {
+                log.error(Errors.ProcBadConfigFile(t.getLocalizedMessage()));
                 throw new Abort(t);
             }
         }