RS participant folder: file count not a number

https://xyz.openolat.com/auth/RepositoryEntry/19202053/Editor/0
Mozilla/5.0 (Windows NT 6.1; Trident/7.0; rv:11.0) like Gecko ^%^ ExceptionWindowController: Throwable occurred, logging the full stacktrace:
>>>stack of 1.cause::java.lang.NumberFormatException: For input string: ""
-> at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
   at java.lang.Integer.parseInt(Integer.java:592)
   at java.lang.Integer.parseInt(Integer.java:615)
   at org.olat.core.gui.components.form.flexible.impl.elements.IntegerElementImpl.getIntValue(IntegerElementImpl.java:95)
   at org.olat.course.nodes.pf.ui.PFEditFormController.validateFormLogic(PFEditFormController.java:219)
   at org.olat.core.gui.components.form.flexible.impl.Form.submit(Form.java:476)
   at org.olat.core.gui.components.form.flexible.impl.Form.submit(Form.java:451)
   at org.olat.core.gui.components.form.flexible.impl.elements.FormSubmit.dispatchFormRequest(FormSubmit.java:77)
   at org.olat.core.gui.components.form.flexible.impl.FormItemImpl.doDispatchFormRequest(FormItemImpl.java:538)
   at org.olat.core.gui.components.form.flexible.impl.Form.evalFormRequest(Form.java:304)
   at org.olat.core.gui.components.form.flexible.impl.FormWrapperContainer.doDispatchRequest(FormWrapperContainer.java:103)