What is the relationship between Projects_Table and Inventory?
And why is there Show All Records at the end?
To perform a find and then immediately turn around and show all records without actually doing anything with the records you just found makes no sense here.
Do you have objects on your layout such as conditional formats, summary fields, calculation fields with aggregate functions such as Sum() that access possibly very large numbers of related records?
Best guess I can make from here, is that your layout has such objects and it's taking a while to update the layout due to the large numbers of records involved. Pressing escape terminates the update of one or more such calculations.
If you remove "Show All Records", do you still get the hourglass?
"What is the relationship between Projects_Table and Inventory?"
It's the allow creation of records on both tables via this relationship using a PK and FK.
"And why is there Show All Records at the end?"
"Do you have objects on your layout such as conditional formats, summary fields, calculation fields with aggregate functions such as Sum() that access possibly very large numbers of related records?"
No, this is a brand new table layout with no summaries, conditional formats, etc. Now, Projects_Table has almost 50000 records.
"If you remove "Show All Records", do you still get the hourglass?"
Now, this is very interesting, if I leave the script running without hitting ESC, it cycles through enter find mode, set field yes, and the results.
What do you want this script to do?
You need to remove show all records from your script as it defeats the purpose of this script.
You refer to two different tables in your script. Inventory and Projects_Table. Presumably, you want to find the records in the Projects_Table that have a related record in Inventory where the Ready_For_Processing field is "yes".
Is Ready_For_Processing a calculation field? If so, is it stored or unstored?
In any case, you need to remove show all records from your script as it defeats the purpose of this script here.
Once you make this change, how many records does this script find?
The fact that you are finding records where the criteria is entered into a related table's record does slow your find. Having 50,000 project records also slows this down. If it is an unstored calculation, it will really slow you down when working with large numbers of records like this. If this is an unstored calculation field, you may need to redesign things so that you can perform this find by entering criteria into a stored/indexed field instead of this unstored calculation field.
You might also try performing this find on the Inventory layout to find the inventory records, then use Go To Related records with the match found set option to then switch back to the Projects_Table layout. This trick works best if the find is only likely to pull up a fairly small number of inventory records. With large numbers of records found, it can be as slower or slower than your current script.
I removed show all records and Ready_For_Processing is not a calculation field.
the script finds 2000 records, which is about right, regardless of how long I take to ESC from it.
Go to Layout ["Details" (Inventory)]
Enter Find Mode 
Set Field [Inventory::Ready_for_Processing; "YES"]
Perform Find 
Go to related record [Show only related records; Match found set; From table: "Projects_Table"; Using Layout: "Consolidated Report" (Projects_Table)]
Go To Layout ["Consolidated Report" (Projects_Table)]
Same results; once I hit ESC it shows what I want.
Thanks for your help, PhilModJunk!!
Something in your layout is taking a long time to update. If it were the find, esc would interrupt the find and you wouldn't see the correct group of records. (Make sure you test this by starting with a found set different from the set you want to see ust to be sure. Do a show all records first or something.)
Since I can't actually see your layout, it's difficult to know what might be taking so long to update. You might try duplicating your layout and modifying your script to run on the duplicate layout, then remove a few items at a time from this new layout until you no longer get the hour glass. When the hour glass no longer appears, take a closer look at the items you just removed from the layout.
I found the problem! When I created this layout I wanted to see if the scrip triggers were my best option, so I set OnLayoutEnter and later on OnModeEnter. I forgot I had these two checked so that's why it kept on loading data and going through a loop
thanks for pointing out to eliminate one thing at the time, until the hourglass was gone!
Do you have FileMaker advanced?
It can be very useful in some of these type issues as you can enable the script debugger and then watch things happen one step at a time. When your script trips a script trigger and that script starts up, you'll see it happen in the debugger...
I do have Advanced and it's time to start using the script debugger.
Thanks for your suggestions; you're awesome, man!!