Wrong syntax for command's '-webstat' parameter

Symptoms

Migration from Parallels Plesk 9.5 shows following warning:

Unable to create a hosting plan: Wrong syntax for command's '-webstat' parameter. 'true' does not match the pattern '/^(none|webalizer|awstats|smarterstats|urchin)$/'.

Cause

The webstat parameter is set up incorrectly in Plesk system database. In turn, this is likely caused by previous failed Plesk upgrades.

mysql> select * from tmpldata where element = 'webstat';
+---------+---------+--------------+
| tmpl_id | element | value        |
+---------+---------+--------------+
|       7 | webstat | true         |
|       9 | webstat | smarterstats |
|      10 | webstat | none         |
|      11 | webstat | webalizer    |
|      12 | webstat | smarterstats |
|      15 | webstat | none         |
|      21 | webstat | none         |
|      22 | webstat | none         |
+---------+---------+--------------+
8 rows in set (0.13 sec)

Resolution

Open properties of domain template and set the proper value to webstat option and save changes.