Render variable in loop is null

Dear all,

following code in Tapestry 5.3.7 makes problems:

<t:zone ...>

<t:form ....>

<t:loop .....>

.... some formelements like text and select and actionlinks
here ....

</t:loop .....>

</t:form ....>

</t:zone ...>

Problem: Inside the loop there is a number of actionlinks each triggering
the removement of one item in the loops source collection. Now the value
enocder throws a nullpointer in its toValue method, because it still tries
to call the toValue method with the client id of the removed loop source
item.
The loops formstae is "VALUES".
How to avoid this?

Any hint is appreciated.

Greetings, Erich