How to fix SELECTION_EMPTY error for courses.students.ubc.ca?

Help and Support
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1

Hello!

I’ve set up distill to help me monitor whether a uni course of mine is full or not full (by selecting the text that says “full” ). However, I haven’t received any email notification when there are changes to that text. I suspect it is because everytime the “full” text disappears, I get a “SELECTION_EMPTY error encountered” . I have no idea how to fix it though! I read up on a similar situation happening to someone else on the forum and saw I might have to manually make a more stable selector? Not sure how to do that though. But my friends have set it up the same way and have had no issues!

For the monitoring options, I have no conditions and “email [my email]” under actions.

Thanks in advance!

2

Hello @snowy17037, following article discusses some of the common reasons and techniques to fix SELECTION_EMPTY error:

https://distill.io/docs/web-monitor/how-to-view-log-of-checks/

I can help troubleshoot it for you if you can share the following:

  1. The URL being monitored for changes
  2. A screenshot of the error details. Error details contains the snapshot of the page when the monitor errored out.
3

Hello,

Here is:

  1. PHIL 120 - Introduction to Critical Thinking - UBC Student Services

image
image1890×930 91.9 KB

I’ve been selecting the “full” on the left hand side.

Thank you!

4

Got it, thanks!

SELECTION_EMPTY error was triggered because the selection no longer matched any content after “Full” text was removed.

A simple solution is to include one more element from the page. In this case, include the page’s title "PHIL 120 Introduction to Critical Thinking" in the page as an additional element. Or, you can monitor the whole row in the table as shown below:

image

Once done, you should be able to get alerts when “Full” status is no longer present.

Hope this helps!