Did you know? Since BC 22 we are facing an issue which we call "JIT Error".
If you run Rec.CalcFields on a page to "calculate" a blob, next time you change the Record you will get the following error:
You can easily reproduce that issue with our repo:
Wait... JIT?
Yes! JIT means Just-In-Time.
"When a record is loaded as a partial record, the obvious question is: What happens when accessing a field that hasn't been selected for loading?
The answer is JIT loading. The platform, in such a case, does an implicit Get on the record and loads out the missing field."
Read more using partial records on https://learn.microsoft.com/en-us/dynamics365/business-central/dev-itpro/developer/devenv-partial-records
This error occurs by using the following Version:
Our Test Scenarios:
Test Page 1:
OnAfterGetRecord -> Rec.CalcFields -> Error
Test Page 2:
OnAfterGetRecord -> NewRec = Rec -> NewRec.CalcFields -> No Error
Test Page 3:
SelectLatestVersion in OnAction trigger -> OnAfterGetRecord -> Rec.CalcFields -> No Error
Test Page 4:
Blob Field shown on the Page -> OnAfterGetRecord -> Rec.CalcFields -> No Error
Test Page 5:
Blob Field hidden on the Page -> OnAfterGetRecord -> Rec.CalcFields -> No Error
First Test:
To reproduce the error in the first test page 62001:
Open the page
Add some entries as shown:
Mark the second or third entry
Click on “Run Action” (two times) o First time: Test Bool will be switched to “true” o Second time: Error
Second Test:
To reproduce the error in the first test page 62001:
Reopen the page after you got the error.
The second entry (if selected before) has Test Bool set to true now:
Mark the second entry
Click on “Run Action” (the error will come up directly and the page will be closed; then you can’t start the page again until you clean your cache)