Annotating labels of a Feature Class with a Table Join in place (read only)

[DucksInaRiver]

I have spent 4 hours on a task that once took me 4 seconds, so hoping you all can provide me with the reasons for my troubles in ArcPro, as well as a solution. I'm losing my mind. 

Geoprocessing tool: Convert Labels to Annotation
Error is 002867: The specified feature layers is not valid.
Error 000622: Failed to execute (ConvertLabelstoAnnotation). Parameters are not valid.
Parameters are as follows: 
Input Map is the Map in which I am working.
Conversion Scale: tried three options that did not resolve the Errors; first option was the nearest Scale to what I know the State level view scales to (around 1:4,100,000 so I selected 1:5,000,000). Second time I tried the highest scale option of 1:100,000,000 and that also failed. Third try (not a charm), I selected the nearest scale to the Feature Layer itself, so 1:500,000.  
Convert: Single Layer - one of the other layers in the Map reads as Unsupported over in the Upgrade window pane in Catalog. Plus, I only want to annotate this particular layer. 
Feature Layer: The named Feature Layer with the displayed labels I want to Annotate
Output Geodatabase: The home gdb in which the Feature Layer currently resides
Annotation Suffix: the default 'Anno'
Extent: Default. Also tried Current Extent which auto changes to As Specified Below and still fails. (The Map is Active, so not sure...)
All options below that are unchecked and when I checked them in different trials I still got a fail error.
Output Layer: the default "GroupAnno". 

Useful information about this feature layer I'm working with

The original feature layer was a shapefile created in ArcMap (version unknown to me). I used Feature to Feature in ArcPro's geoprocessing to import it over to a new gdb within the Project folder of ArcPro. It needed a new Field and data down the column which took me 5 hours yesterday to figure out how to do that particular simple task, but I eventually successfully exported the attribute table with an added Field I added while it was in Pro, entered the new data (number) down the new field column in the exported Excel doc., then Joined it to the original Feature layer and successfully displayed those values as labels in Layout view in ArcPro. The labels aren't where I want them to be so I'd like to annotate them. First off, why the expletive is this more difficult than the two clicks it took in ArcMap? 

I investigated the Feature Layer from the Catalog pane and it reads as 32-bit, so if that's part of the problem then I don't know how to solve it because I thought that importing via Feature class to Feature class geoprocess within Pro would handle that. Found this Help page related to the Annotation process but can't figure out how to "Perform Pre-Requisite Check" so it's not helpful. 

I confirmed that the Joined table indexes are Read Only. Don't know what to do with that information or how to make it not Read Only if that's the problem. 

General gripes and grievances (for anyone else out there who's struggling and as frustrated as me)

I've lost countless hours of productivity and their tutorials are absolutely useless for anyone who just wants to import some data and make a simple map. ESRI, if you are reading this, for pete's sake, PLEASE do some due diligence and learn more about what a lot of your users actually need in order to do their jobs. The majority of us are not modeling earthquake epicenters and analyzing response times. We just want to use our data we've been using in ArcMap, update it as needed, and then make a map for context of a project. 

The vast majority of the data I'll be working with is coming from ArcMap created data, and these aren't MXDs that I can just batch convert. It's randomly housed feature classes in old gdbs or shapefiles in an external drive, network drives, and local drive folders. It's basically the equivalent of a storage room with a collection of haphazardly labeled boxes that have thousands of pages on office paper, colored construction paper, and laminated sheets and I need to pull these files out of their dusty old boxes and scan them into editable PDFs of the same consistent quality and format. That's not what I'm doing, but that's my simile I'm using for now. I am desperate for resources that will make these processes more efficient and still be able to USE the data the way I used it in ArcMap. I knew Pro would be a challenge, but this is unbelievable.

[RhettZufelt]

Lots of issues with Pro 3 and Excel, especially if you have not made sure to remove/install the proper excel drivers, have both sets installed if ArcMap is also installed, etc.

First thing I'd try is to save the Excel table as a stand alone ESRI table, and join that to the FC and not the Excel table.  Trying the same thing with no connections to Excel in the project at all will at least let you rule that out as a possible cause.

R_

[DucksInaRiver]

Thank you, RhettZufelt, could you please indicate which drivers I need to look into? I would have to run it by our IT administrator. No ArcMap on the computer, but it's definitely not uncommon for our IT folks to not be aware of what all we need for GIS. 

Could you explain to me how your suggestion to export as an ESRI table changes the process? Does it make it not "read only?" Is the Read Only designation a suspected problem? 

How would I go about editing the table in that format outside of Pro? I will soon be receiving excel sheet based data from a myriad of sources, and so I need to be able to quickly copy/paste columns into exported attribute tables and then join those new data tables to spatial data sets such as tax parcel feature layers (polygons). 

So, funny thing though...yesterday, I tried to annotate again and had found my way to an Annotate button somewhere within the ribbon (which I can't seem to find again in this moment), and when I clicked on that the whole thing worked. The only difference I noticed was that the scale was precise to the scale of my map in Layout view. I am trying to re-create my process right now but I can't seem to find my way back to it. 

[RhettZufelt]

Need to make sure you have the Microsoft Access Database Engine 2016 Redistributable 64-bit driver for Excel installed.  Since you have Pro installed already, you must have an updated .NET Desktop Runtime already.  Documentation here.

Since at least the early 90's, ESRI products have had "issues" when using Excel tables in GIS.  Often it works, sometimes not, changes field types, etc., etc., etc.  So, if having problems, the first thing to try is to eliminate Excel data from the process.

If you successfully export the Excel to a standalone table in SDE or FGDB (I use a different project for this so the Excel table is never loaded into my working project), and then join to that table instead of the Excel, any "Excel" related issues will go away.  It is a good step in narrowing down the issue(s).

I would try to edit/calculate most of my values inside of Pro.  If I want/need to do that in Excel, make the Excel table as needed, convert to standalone table, join to the standalone table ad do whatever work is needed.

Not sure about the Annotate button, but if you right-click the layer, Convert Labels, Convert Labels To Annotation is there.  It appears to open the same GP tool, but Pro is notorious for running "differently" when running from the ribbon vs the tool.  If you have issues with one method, you should try the other.

Oh yeah, if you are loading/joining Excel data and have the Excel file open in Excel at the time, it can/will spawn various errors that really don't make sense.  In this case, close Excel first, then try.

R_