diff --git a/AprilTags-for-FTC-Blocks.md b/AprilTags-for-FTC-Blocks.md
index 6e01d44..35ac295 100644
--- a/AprilTags-for-FTC-Blocks.md
+++ b/AprilTags-for-FTC-Blocks.md
@@ -170,6 +170,8 @@ Now the file **`AprilTagIdCode.java`** is downloaded to your computer.
In OnBot Java, click the **`Upload Files`** icon. This places the file in the **`teamcode`** folder.
+Note: Windows might add the **".txt"** extension **without showing you**. This file won't upload to the **`teamcode`** folder as required. In Windows Explorer, click the **View** tab at the top, then check the box to show **File name extensions**. Now you can see and remove the **".txt"** extension using **Rename** or the **F2 key**. Then try the upload again.
+
Still in OnBot Java (OBJ), click the filename to open it. **Read through the Java code**, looking at the 8 methods and their myBlock annotations. Each one will become a myBlock that appears in the Blocks menu, under Java Classes.
Each annotation includes a short comment describing the method. In general you'll use these methods in the order they are defined:
@@ -217,6 +219,8 @@ Follow the same steps as above, to download the Java code to your computer:
In OnBot Java, click the **`Upload Files`** icon to place this file in the **`teamcode`** folder.
+Again, Windows might add the **".txt"** extension **without showing you**. In Windows Explorer, click the **View** tab at the top, then check the box to show **File name extensions**. Remove the **".txt"** extension using **Rename** or the **F2 key**, then upload.
+
There's no need here to study this Java code; it's highly technical and won't be edited for this exercise. The program collects a camera image using OpenCV, searches it for one or more AprilTags, and draws a colorful box projecting from each AprilTag. This pipeline can also provide location and orientation data, but we focus here on simply getting an AprilTag ID code.
[[Return to Top|https://github.com/FIRST-Tech-Challenge/FtcRobotController/wiki/AprilTags-for-FTC-Blocks]]