Error 259 on webload for read only non string fields without a value in DSP

Summary:
Uniface:
A DSP has a read only non string field
(like numeric editbox / a boolean checkbox / a date datepicker)
without a value assigned and with syntax property NED (so read only).
After a round trip to the server error 259 - Hash security value mismatch on
field - occurs during webload.

Environment:
+Uniface Version : 9 / 10
+Operating System : OS independent
+Database : DBMS independent
+Browsers : Browser independent

Reproduction scenario
1. Start a DSP with a numeric editbox / a boolean checkbox / a date datepicker
with a value assigned and with syntax property NED (so read only)
2. Press a button for a round trip to the server

Expected Result
Field values returned , no errors.

Actual Result
Runtime error:
webload failed
Error=259
Description=Hash security value mismatch on field