Fix server crashes: tcmalloc and workshop collection issues

- Add automatic tcmalloc disable in start scripts to prevent 'large alloc' segfaults
- Add warnings and documentation about workshop COLLECTION vs addon IDs
- Expand troubleshooting section with solutions for common crashes
- Document that -authkey deprecation warning can be safely ignored

Fixes:
- tcmalloc: large alloc XXXXXXX bytes == (nil) followed by Segmentation fault
- Item is not a collection! error when using addon ID instead of collection ID
- Missing 32-bit libraries warning with installation instructions

README.md

@@ -123,6 +123,29 @@ docker-compose pull && docker-compose up -d
 
 ## 🛠️ Troubleshooting
 
+### Server crashes with "tcmalloc: large alloc" error
+This is a memory allocation failure in Google's tcmalloc library. The fix is applied automatically by our start scripts, which disable tcmalloc. If you still see this error:
+```bash
+# Manually disable tcmalloc
+mv /home/gmod/serverfiles/bin/libtcmalloc_minimal.so.4 /home/gmod/serverfiles/bin/libtcmalloc_minimal.so.4.disabled
+```
+
+### "Item is not a collection!" error
+```
+Processing collection XXXXX...
+   Item is not a collection!
+```
+**Cause:** You're using an individual addon ID instead of a collection ID.
+
+**Fix:** 
+1. Go to `https://steamcommunity.com/sharedfiles/filedetails/?id=YOUR_ID`
+2. If it shows a single addon (not a "Collection"), you need to create a proper collection
+3. Create a new collection on Steam Workshop containing your desired addons
+4. Use that collection's ID instead
+
+### "-authkey is no longer required" warning
+This warning can be safely ignored. The `-authkey` parameter was deprecated by Garry's Mod and is no longer needed for workshop content.
+
 ### Server won't start
 - Check that `SRCDS_TOKEN` is set
 - Verify ports 27015-27020 are open
@@ -130,13 +153,26 @@ docker-compose pull && docker-compose up -d
 
 ### Workshop content not downloading
 - Verify collection is public
-- Check `WORKSHOP_COLLECTION` is set correctly
+- Check `WORKSHOP_COLLECTION` is set correctly (must be a Collection ID, not an addon ID!)
 - Ensure server has internet access
 
 ### Players can't connect
 - Ensure firewall allows UDP/TCP 27015
 - Verify server is properly registered with Steam
 
+### Missing 32-bit libraries warning
+```
+WARNING: Failed to load 32-bit libtinfo.so.5 or libncurses.so.5.
+```
+Install the required libraries:
+```bash
+# Debian/Ubuntu
+sudo apt-get install lib32tinfo5 libncurses5:i386
+
+# CentOS/RHEL
+sudo yum install ncurses-libs.i686
+```
+
 ## 📜 License
 
 MIT License - Free to use and modify.