We faced the same problem, after lot of re-search we found a solution:
Please do this:
1) Just take the field for which it is showing the exclamatory mark with yellow triangle. In your case, it is plant/material. For us, it was plant.
2) Go to OMYZ and click access sequence. Click on your relevant access sequence and click control in the left.
3) now click on the relevant condition table, and click field in the left.
4) now click the plant/material fields, and click the "field catalogue" button in the bottom.
5) there, double click the relevant field of plant &material and press enter until it allows you to save.
6) now delete the current condition records and maintain it again.
It should work now.