Unable to cast object of type 'System.TimeSpan' to type 'System.IConvertible'.

[bbseven]

I have gotten an error in my AppSheet with no real explanation other than this error message. Stopped me dead in my tracks. I went about recreating it from scratch, and just as I was finishing up, it happened on the recreation. Once this error occurs, it seems to corrupt the entire project. Has anyone seen this, and have any suggestions? The only thing I could add is that I am using airtable as the datasource, which seems to be problematic.

[WillowMobileSys]

Please forward that error message to Appsheet.  That is NOT meant to be an error surfaced to app creators but rather reflects an issue in code used to implement the AppSheet platform.

"TimeSpan" is the equivalent of the Duration type.  Check any Duration type columns for noticeable issues.  Also take a look at any Date and/or Time calculations you may be doing.  Those will return Duration type results.

[bbseven]

Yes, just narrowed this down! It has to do with taking TOTALMINUTES from two duration columns and subtracting them. Important to note that you need to remove this calculation and then regenerate the column structure to get it to work again.

[bbseven]

24 hours of pain with this bug, but I narrowed it down to using a Duration column type in airtable in a virtual column. This causes the issue and the only way to fix it is to remove the virtual column and regenerate the column structure. The hint was that whenever regenerating, duration columns convert to decimal and need to be changed back every time. Seems like a legitimate bug that can make using airtable very painful.

[gregdiana1]

Glad you sorted it out but one has to realize that the display format in As and that in the spreadsheet may differ or need to differ. This is an often accusing but not well-known issue that takes some head-bashing to resolve just as you had to do.