diff --git a/README.md b/README.md
index 8f85d1e..fbf57ac 100644
--- a/README.md
+++ b/README.md
@@ -46,6 +46,18 @@ docker run -d -p 8080:8080 gcr.io/tenox7/wrp:latest
 * Server Gateway should run on a modern hardware/os that supports memory hungry Chrome.
 * Client Browser needs to support `HTML FORMs` and `ISMAP`. Typically Mosaic 2.0 would be minimum version for forms. However ISMAP was supported since 0.6B, so if you manually enter url using `?url=...`, you can use the earlier version.
 
+## Troubleshooting
+
+### I can't get it to open
+
+This program does not have a GUI and is run from the command line. You may need to enable executable mode, for example on Mac:
+
+```bash
+$ cd ~/your-download-directory
+$ chmod +x wrp-amd64-macos
+$ ./wrp-amd64-macos -t png
+```
+
 ## History
 
 * In 2014, version 1.0 started as a *cgi-bin* script, adaptation of `webkit2png.py` and `pcidade.py`, [blog post](https://virtuallyfun.com/2014/03/03/surfing-modern-web-with-ancient-browsers/).