The number of defined parameters is not equal to the number of cell definitions in the parameter panel

 This issue can occur when a developer copies a report from an existing design and tries to make the changes to the dataset. 

There are parameters passed between the AX system and SSRS framework and these need to be in Sync. The parameters are stored at 3 levels and it needs to be in Sync. Sometimes it can happen that due to the edits one makes these move out of Sync in such cases we have to manually fix it. 

Its important that for every parameter at the report level, there is a corresponding parameter at the dataset level. 

The other odd place where the parameters are saved is in the XML file and it can sometimes not be seen/referred on the screen. Hence to fix these we should open the report using an xml editor. Right click the report and choose to open with XML editor.

Once the xml editor is opened , one can see that there parameters referred in the XML file which do not exist on the dataset. These are from a previous dataset PromotionSalaryDS which now is probably removed and hence the mismatch. 

We should manually delete these parameters to match the list as per the report parameters. 

You will also have to delete the parameters if they are referred in the Parameter cell definition. Please ensure that you delete each xml block as a unit. One unit is highlighted below it starts with CellDefinition and ends with /CellDefinition