Add troubleshooting docs

Author: mbtools

src/user-guide/README.md

@@ -14,6 +14,7 @@ index: false
 - [Uninstalling](getting-started/uninstall.md)
 - [UI Layout](getting-started/ui-layout.md)
 - [UI Features](getting-started/ui.md)
+- [Troubleshooting](getting-started/troubleshooting.md)
 
 ### Setup
 

src/user-guide/getting-started/README.md

@@ -14,3 +14,4 @@ dir:
 - [Uninstalling](uninstall.md)
 - [UI Layout](ui-layout.md)
 - [UI Features](ui.md)
+- [Troubleshooting](troubleshooting.md)

src/user-guide/getting-started/troubleshooting.md

@@ -0,0 +1,64 @@
+---
+title: Troubleshooting
+category: getting-started
+order: 60
+---
+
+The most common issues with abapGit are listed here
+
+## HTTP Errors
+
+### 401 - Unauthorized and 403 - Forbidden
+
+Reading public repositories typically does not require authentication to the git server. However, accessing private repositories or trying to update repositories in general will require authentication.
+
+- Check your user and password
+- Check if the server requires a token as the password (for example, GitHub)
+- Test your credentials using a command line tool (git, curl, etc)
+
+### 404 - Not Found
+
+- Check if the git servers requires `.git` at the end of the repository URL (for example, GitLab)
+- Check if it's a private repository that requires authentication
+
+### 407 - Proxy Authentication Required
+
+Also: `ICM_HTTP_SSL_ERROR`, `SSSLERROR_SSL_READ`, `SSSLRC_CONN_CLOSED`
+
+- Check the proxy configuration in abapGit [Global Settings](/user-guide/setup/settings-global.html)
+- Check the [SSL Setup](/user-guide/setup/ssl-setup.html)
+- Use the [SSL Test Tool](/user-guide/setup/ssl-test.html) to verify the connection
+
+### 411 - Connection Failed
+
+Also: `NIECONN_REFUSED`
+
+- Check SAP system parameters in [SAP Note 510007](https://me.sap.com/notes/510007)
+
+### 421 - Misdirected Request
+
+Also: `ICM_HTTP_SSL_PEER_CERT_UNTRUSTED`, `SSSLERR_PEER_CERT_UNTRUSTED`
+
+- Check the [SSL Setup](/user-guide/setup/ssl-setup.html)
+- Use the [SSL Test Tool](/user-guide/setup/ssl-test.html) to verify the connection
+
+## SAP GUI
+
+Try to run the latest version of SAP GUI. Older version are known to have issues. SAP GUI for Windows is the most used and tested client.
+
+- Check the [SAP GUI Setup](/user-guide/setup/sapgui.html)
+
+## Supported Object Types
+
+Which object types are supported in your system depends on the combination of abapGit and SAP releases. 
+
+- Check "Debug Info" from the tools menu on the repository overview (shows the object types supported in your system)
+- Check the [List of Supported Object Types](/user-guide/reference/supported.html) (most recent release)
+- Check [Requests for Supporting New Object Types](https://github.com/abapGit/abapGit/issues/5912) (unchecked means "not supported")
+
+## User Exits
+
+Behaviour of abapGit can be changed using [User Exits](/user-guide/reference/exits.html). 
+
+- Check "Debug Info" from the tools menu on the repository overview (shows which exits are active in your system)
+- In case of issues, deactivate all exits to narrow down the root cause.