Symptoms
- 
Several actions (installing an extension, migrate a site, clone a WP site) fail with the following error being returned in %plesk_dir%adminlogsphp_error.log:C:> [2023-06-08 15:13:40] 19032:64822863f3803 ERR [panel] "C:Program Files (x86)Pleskadminbincrontabmng" get psaadm failed with code 1. 
- 
Backup operations end with the warning: Warning: Server "trusting-galois.103-20-212-37.plesk.page" 
 Unable to back up scheduled tasks. Error: crontabmng failed: Line (1): System.FormatException: Input string was not in a correct format.
 at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal)
 at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info)
 at psa.scheduler.device.Parser.GetNumber(Int64 low, String[] names)
 at psa.scheduler.device.Parser.GetRange(Int64 low, Int64 high, String[] names)
 at psa.scheduler.device.Parser.Parse_6_5_FileLine()
 at psa.scheduler.device.PSAScheduler.Load_6_5_File(StreamReader sr)
- 
Executing any WordPress Toolkit CLI command fails: C:> plesk ext wp-toolkit --list 
 crontabmng failed: Line (1): System.FormatException: Input string was not in a correct format.
 at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal)
 at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info)
 at psa.scheduler.device.Parser.GetNumber(Int64 low, String[] names)
 at psa.scheduler.device.Parser.GetRange(Int64 low, Int64 high, String[] names)
 at psa.scheduler.device.Parser.Parse_6_5_FileLine()
 at psa.scheduler.device.PSAScheduler.Load_6_5_File(StreamReader sr)
 (Error code 1)
- 
The file psaadm in path C:Program Files (x86)PleskSchedulesis missing or corrupted.
- 
The following command fails with: C:> plesk sbin crontabmng configure-default 
 Line (1): System.FormatException: Input string was not in a correct format.
Cause
Crontab's configuration file for the psaadm user is corrupted, therefore any action that involves crontabmng fails.
Resolution
- Connect to the server via RDP
- Go to C:Program Files (x86)PleskSchedules
- Create a copy of psaadm file
- Replace psaadm file with the one attached or from a test server