diff --git a/src/emu/attotime.h b/src/emu/attotime.h
index d2209ea9c32..75c55e4638c 100644
--- a/src/emu/attotime.h
+++ b/src/emu/attotime.h
@@ -120,7 +120,7 @@ public:
 	/** @return the seconds portion. */
 	constexpr seconds_t seconds() const { return m_seconds; }
 
-	static constexpr attotime from_double(double _time);
+	static attotime from_double(double _time);
 	static attotime from_ticks(UINT64 ticks, UINT32 frequency);
 	/** Create an attotime from a integer count of seconds @seconds */
 	static constexpr attotime from_seconds(INT32 seconds) { return attotime(seconds, 0); }
@@ -376,7 +376,7 @@ inline attotime attotime::from_ticks(UINT64 ticks, UINT32 frequency)
 }
 
 /** Create an attotime from floating point count of seconds @p _time */
-inline constexpr attotime attotime::from_double(double _time)
+inline attotime attotime::from_double(double _time)
 {
 	seconds_t secs = floor(_time);
 	_time -= double(secs);
diff --git a/src/emu/dimemory.cpp b/src/emu/dimemory.cpp
index 56543ae551a..0081062c38c 100644
--- a/src/emu/dimemory.cpp
+++ b/src/emu/dimemory.cpp
@@ -9,7 +9,6 @@
 ***************************************************************************/
 
 #include "emu.h"
-#include "validity.h"
 
 
 //**************************************************************************
diff --git a/src/emu/divtlb.cpp b/src/emu/divtlb.cpp
index 01be30919cb..3f4266a2285 100644
--- a/src/emu/divtlb.cpp
+++ b/src/emu/divtlb.cpp
@@ -10,7 +10,6 @@
 
 #include "emu.h"
 #include "divtlb.h"
-#include "validity.h"
 
 
 
diff --git a/src/emu/validity.cpp b/src/emu/validity.cpp
index f4c80a8f205..cfbad976d66 100644
--- a/src/emu/validity.cpp
+++ b/src/emu/validity.cpp
@@ -270,6 +270,10 @@ void validity_checker::validate_end()
 
 void validity_checker::validate_one(const game_driver &driver)
 {
+	// help verbose validation detect configuration-related crashes
+	if (m_print_verbose)
+		output_via_delegate(OSD_OUTPUT_CHANNEL_ERROR, "Validating driver %s (%s)...\n", driver.name, core_filename_extract_base(driver.source_file).c_str());
+
 	// set the current driver
 	m_current_driver = &driver;
 	m_current_config = nullptr;
@@ -303,7 +307,9 @@ void validity_checker::validate_one(const game_driver &driver)
 	// if we had warnings or errors, output
 	if (m_errors > start_errors || m_warnings > start_warnings || !m_verbose_text.empty())
 	{
-		output_via_delegate(OSD_OUTPUT_CHANNEL_ERROR, "Driver %s (file %s): %d errors, %d warnings\n", driver.name, core_filename_extract_base(driver.source_file).c_str(), m_errors - start_errors, m_warnings - start_warnings);
+		if (!m_print_verbose)
+			output_via_delegate(OSD_OUTPUT_CHANNEL_ERROR, "Driver %s (file %s): ", driver.name, core_filename_extract_base(driver.source_file).c_str());
+		output_via_delegate(OSD_OUTPUT_CHANNEL_ERROR, "%d errors, %d warnings\n", m_errors - start_errors, m_warnings - start_warnings);
 		if (m_errors > start_errors)
 			output_indented_errors(m_error_text, "Errors");
 		if (m_warnings > start_warnings)
diff --git a/src/emu/validity.h b/src/emu/validity.h
index a25a922e7b6..36b40df80c9 100644
--- a/src/emu/validity.h
+++ b/src/emu/validity.h
@@ -51,7 +51,7 @@ public:
 	int region_length(const char *tag) { return m_region_map.find(tag)->second; }
 
 	// generic registry of already-checked stuff
-	bool already_checked(const char *string) { return m_already_checked.insert(string).second; }
+	bool already_checked(const char *string) { return !m_already_checked.insert(string).second; }
 
 	// osd_output interface
 
diff --git a/src/mame/machine/slapstic.cpp b/src/mame/machine/slapstic.cpp
index 2d1e83aae67..50d14f2e4c2 100644
--- a/src/mame/machine/slapstic.cpp
+++ b/src/mame/machine/slapstic.cpp
@@ -182,7 +182,6 @@
 
 
 #include "includes/slapstic.h"
-#include "validity.h"
 
 
 extern const device_type SLAPSTIC = &device_creator<atari_slapstic_device>;