The multipoint geometry could be causing the issue. The geometry should be "point".
Use the following steps to convert the above data to point feature class.
1. Add two new fields in the attribute table, viz., "X" and "Y". Calculate the respective X and Y coordinates using CALCULATE GEOMETRY. Choose "Decimal Degrees" as units.
2. Using Table to Excel tool, convert the table to Excel.
3. Open the excel file in MS Excel. Delete the Geometry field.
4. In ArcMap, File > Add Data > Add XY data. Use appropriate spatial reference (e.g. GCS_WGS_1984 or any other appropriate GCS).
5. Export the Event layer to a Feature class/shapefile.
Then try the Spatial Join once again.
Think Location