When I open my map projects in ArcGIS Pro, the previously joined data is now all <null> in the attribute table

[Srygl1sl]

I know that the join was successful and the data was not null in the past, because I have made and exported maps from this project file.

However, when I opened it today the attribute tables for all of my layers show the joined variables, but they are all populated with <null> as the value. What is causing this and how can I resolve it and prevent it with future projects?

[SLouq]

were there any changes to your join field?

[Srygl1sl]

No- nothing has changed.  I have a standalone table with the data I needed joined and nothing has been changed on that table. The data in that standalone table is also still fully populated. Only the attribute tables for all of my layers have the null values.

[MrRamonG]

Were there any changes to the joined file, file name or file path?

[Srygl1sl]

Nope, no changes. The join is to a standalone table in the map contents and nothing has changed with it.

[SLouq]

Have you checked the data type for each field? ArcGIS Pro could be interpreting one of the fields as a different data type

[DavidPike]

Where is this standalone table located?  Not sharepoint or cloud or anything?

[Srygl1sl]

My mistake- it is joined to a .xlsx. Nothing about that file or its location has changed since the original maps were made and exported.

I have installed the drivers and had this connection working in the past, but it seems that Pro is no longer connecting to excel files. I got this error when I tried to select the relevant file in my Catalog Pane: "exception of  type 'ArcGIS.Desktop.Core.Geoprocessing.GPItemException"

[Srygl1sl]

Apologies and correction.

The join is to an excel table. The location has not changed, nor has any of the content of the .xlsx. I have installed the drivers for using excel documents and had it working in the past in order to make these maps originally, but it appears that ArcGIS Pro is no longer connecting to excel files as when I went to select the .xlsx in my Catalog Pane I got the following error:

"exception of  type 'ArcGIS.Desktop.Core.Geoprocessing.GPItemException"

[SLouq]

you should be able to access an Excel file from Pro. No drivers needed like in ArcMap. I can bring in Excel tables in Pro and perform a join. Have you tried right clicking and Display XY coordinates to make the Excel table a feature and then tried joining the tables?