DESCRIPTION
This error you may be facing while making a simple call to apex method from LWC and any record is being created, updated or deleted.
SOLUTION
If the apex method you are invoking from LWC is annotated as cacheable=true
then you can not make any DML in that context. So, in order to avoid this issue, please remove this cacheable=true.
Previously:
@AuraEnabled(cacheable=true) public static String updateStatus(Id caseId) { Case c = new Case(Id= caseId); c.Status = 'New'; update c; }
Now
@AuraEnabled public static String updateStatus(Id caseId) { Case c = new Case(Id= caseId); c.Status = 'New'; update c; }