I have an installation where I changed the names of the xoops_lib and xoops_data folders but located them in the root folder.

I want to move them out of the root folder but after doing so and editing mainfile.php to reference the new locations, I get the following error:

Error: Smarty error: the $compile_dir '/xxxxx_data/caches/smarty_compile' does not exist, or is not a directory.

Apparently I am missing something. What are the proper steps to moving the xoops_lib and xoops_data folders?

try check the permission for smarty_compile foler

Smarty compile permissions are wide open, 777.

Check also the permissions of the parent directories.
Quote:
You have to adapt the XOOPS_PATH and XOOPS_VAR_PATH in mainfile.php to the new paths.

Quote:should it not be a longer path like /home/youraccount/xxxxx_data/caches/smarty_compile ?

Despite mainfile.php pointing to the new path, some file seems to be looking for the old path.

Permission was 755 for one parent directory, but changing to 777 has not resolved it.

Here is the complete error:
Error: Smarty error: the $compile_dir '/xxxxoops_data/caches/smarty_compile' does not exist, or is not a directory.
Backtrace:
/class/smarty/Smarty.class.php (1092)
/class/smarty/internals/core.write_compiled_resource.php (20)
/class/smarty/Smarty.class.php (1430)
/class/smarty/Smarty.class.php (1260)
/class/theme_blocks.php (141)
/class/theme_blocks.php (92)
/class/theme_blocks.php (36)
/class/theme.php (243)
/class/theme.php (73)
/header.php (66)
/index.php (77)

I moved the contents of the xoops_data folders from one location to another. Should I delete the files in any of the directories under xoops_data?

Here is what the mainfile.php looks like now however if I remove the old xoops_data folder from the root directory, the site fails with the error noted above.

// For forward compatibility
// Physical path to the XOOPS library directory WITHOUT trailing slash
define( 'XOOPS_PATH', '/home2/mysite/newfolder/xoops_lib' );
// Physical path to the XOOPS datafiles (writable) directory WITHOUT trailing slash
define( 'XOOPS_VAR_PATH', '/home2/mysite/newfolder/xoops_data' );
// Alias of XOOPS_PATH, for compatibility, temporary solution
define("XOOPS_TRUST_PATH", XOOPS_PATH);

You have to empty the cache and template_c folders (leave index.html) and do an update of the system module.

I removed all files except index from the xoops_data/caches/smarty_cache, smarty_compile and xoops_cache folders.
Same for templates_c.
Double check of mainfile.php to point to the new location.

Update the system module and the condition persists.

Something other than mainfile.php is looking for the old xoops_data folder.

I tried running the upgrade again and found it indicated that the 2.0.18 to 2.3.0 upgrade was required. I had done this before, I'm certain.

The Upgrade did not recognize the path of xoops_data so I edited that path and continued. Success indicated after upgrade.

Update of system still puts the files into the wrong (old) place.

I had questions about this also. The directions are not clear as to where to move them to, if you should move AND rename or just do one and then what files/code should be edited (if any) after the move is made.

You should alter your directory structure as depicted in figure 1 or 3, while fig 2 is the default insecure installation.
After the move of the directories, you have to adapt the XOOPS_PATH and XOOPS_VAR_PATH in mainfile.php to the new paths.