Hi Rajack,
We need more information concerning your installation (see here!) and info concerning all your installed plugins (with, version info for the plugins!).
We ready discussed similar problems here , did you already check
- Wiki: Save / View Editions does not work
- Wiki-Plugin: Error Message when save Page with emojis
- Kanboard 1.2.36: Can not save newly created or edited Wiki page
?
Did your problem appear after update of KANBOARD or a plugin?
Currently I think that (3) might be concerning your problem.
CU
Rainer