diff --git a/Compatibility-issues.md b/Compatibility-issues.md
index f697631..3bfbbbc 100644
--- a/Compatibility-issues.md
+++ b/Compatibility-issues.md
@@ -75,4 +75,17 @@ Arduino IDE 1.6.6 bug [#4075](https://github.com/arduino/Arduino/issues/4075) ma
 error: 'namespaceArduinoJson' does not name a type
 ```
 
-You need to upgrade to 1.6.7.
\ No newline at end of file
+You need to upgrade to 1.6.7.
+
+## Arduino Library Manager doesn't list the latest versions of ArduinoJson
+
+This is a very common issue.
+If ArduinoJson doesn't appear in Libray Manager, or if only old versions are listed, try to delete the local cache.
+This will force the Libray Manager to download the library list from scratch.
+
+For example, on Windows, you need to delete:
+
+* `%LOCALAPPDATA%\Arduino15\library_index.json`
+* `%LOCALAPPDATA%\Arduino15\library_index.json.tmp.gz`
+
+You don't even need to close Arduino, just re-open the library manager.
\ No newline at end of file