diff --git a/infrastructure/kasm.md b/infrastructure/kasm.md
index 281a9ed..63baa0e 100644
--- a/infrastructure/kasm.md
+++ b/infrastructure/kasm.md
@@ -1,6 +1,29 @@
-# KASM Cheat-Sheet
-## Custom Images
+# KASM Workspaces
+...
 
+---
+## Add self-signed SSL Certificates
+...
+
+1. Stop the kasm services
+```
+sudo /opt/kasm/bin/stop
+```
+
+2. Replace `kasm_nginx.crt` and `kasm_nginx.key` files
+```
+sudo cp <your_cert> /opt/kasm/current/certs/kasm_nginx.crt
+sudo cp <your_key> /opt/kasm/current/certs/kasm_nginx.key
+```
+
+3. Start the Kasm Services
+```
+sudo /opt/kasm/bin/start
+```
+
+---
+## Custom Images
+...
 
 ### Add Images in KASM
 > [!attention]
@@ -14,4 +37,46 @@
 	"devices":["dev/net/tun","/dev/net/tun"],
 	"sysctls":{"net.ipv6.conf.all.disable_ipv6":"0"}
 }
-```
\ No newline at end of file
+```
+
+
+---
+## Troubleshooting
+...
+
+### Database
+...
+
+```
+sudo docker exec -it kasm_db psql -U kasmapp -d kasm
+```
+
+### Delete invalid users from user_groups table
+...
+
+1. Check table for invalid entries
+```
+kasm=# select * from user_groups;
+            user_group_id             |               user_id                |               group_id
+--------------------------------------+--------------------------------------+--------------------------------------
+ 07c54672-739f-42d8-befc-bb2ba29fa22d | 71899524-5b31-41ac-a359-1aa8a008b831 | 68d557ac-4cac-42cc-a9f3-1c7c853de0f3
+ e291f1f7-86be-490f-9f9b-3a520d4d1dfa | 71899524-5b31-41ac-a359-1aa8a008b831 | b578d8e9-5585-430b-a70b-9935e8acaaa3
+ 07b6f450-2bf5-48c0-9c5e-3443ad962fcb |                                      | 68d557ac-4cac-42cc-a9f3-1c7c853de0f3
+ 8c4c7242-b2b5-4a7a-89d3-e46d24456e5c |                                      | b578d8e9-5585-430b-a70b-9935e8acaaa3
+```
+
+2. Delete invalid entries from the table:
+```postgresql
+delete from user_groups where user_id is null;
+```
+
+3. Verify table
+```
+kasm=# select * from user_groups;
+            user_group_id             |               user_id                |               group_id
+--------------------------------------+--------------------------------------+--------------------------------------
+ 07c54672-739f-42d8-befc-bb2ba29fa22d | 71899524-5b31-41ac-a359-1aa8a008b831 | 68d557ac-4cac-42cc-a9f3-1c7c853de0f3
+ e291f1f7-86be-490f-9f9b-3a520d4d1dfa | 71899524-5b31-41ac-a359-1aa8a008b831 | b578d8e9-5585-430b-a70b-9935e8acaaa3
+(2 rows)
+```
+