Thanks for your feedback.

Thank you very much for addressing this so quickly!

I tested the development version and confirmed that I can now enter and save up to 255 characters in the Proxy hostname field.

(Although I haven't tested the actual update check through a proxy server yet, the UI input and saving behavior work perfectly.)

I really appreciate your quick fix!

I'm sending you an email with a development version of WinSCP to the address you have used to register on this forum.

Thanks for your report.

I have added this issue to the tracker:
Issue 2456 – Increase length limit of proxy host name for updates preferences
You can vote for it there.

Hi,

I would like to report an issue (or request a change) regarding the Proxy hostname length limit in the Preferences dialog.
In contrast, the Login dialog's Hostname field allows input longer than 50 characters without any issues.
Environment:

• WinSCP version: 6.5.6
  
• OS: Windows 11 Pro 24H2
  

Steps to reproduce:

1. Open the Preferences dialog (Options > Preferences)
   
2. Select Updates in the left panel.
   
3. Under the Connection section, select the Use proxy server radio button.
   
4. Try to enter a hostname with more than 50 characters into the Proxy hostname field.

Observed behavior:
Input is restricted to 50 characters maximum. When attempting to type the 51st character, a system beep sounds and no further characters are accepted.

Source code reference:
In source/forms/Preferences.dfm (around line 2290), the UpdatesProxyHostEdit component has MaxLength set to 50:

It seems this MaxLength = 50 setting is enforcing the 50-character limit on this field.

Since hostnames (such as FQDNs in cloud environments) can easily exceed 50 characters, could you please consider extending or removing this limit to match the regular session host name field?

Thank you!