It looks like the function that you applied changes the pixel type of the item(s) to a different pixel type than the mosaic. You should be fine with sticking to 32bit floating point. Fixes for one item with the problem or multiple items below assuming you added the unit conversion function.
Easy fix for one item: Use the error in the analyzer (right-click) and select the associated item. Then use the raster viewer (select the raster cell in the selected row and click on the small arrow inside the cell)->Functions tab. Right-click on the unit conversion function function->Properties->General page set output pixel type to the pixel type of the mosaic.Click OK then click Apply and you should be good to go.
Multiple items: Use the error in the analyzer (right-click) and select the associated items. Use the batch function editor (right-click on footprint sub-layer of the mosaic->Selection->Batch Edit Raster Functions) and pick the Edit option->Search by function name->Pick the Unit conversion function->General tab set output pixel type to the pixel type of the mosaic->Click Next->OK->Next->Finish. That should fix all the items.
Please let me know if this works or if you have any questions.
-Prashant