FatalException *** -[__NSCFConstantString stringByAppendingString:]: nil argument -[NSPlaceholderString initWithCharactersNoCopy:length:freeWhenDone:]

[owenkealey]

Hi,

I have an app with about 800 users and the library works for 99% of people, but I saw this in Crashlytics today.

Any thoughts? I can provide more info if needed.

[aboedo]

Is your app deleting NSUserDefaults? If so, that would explain the crash.
If that is the case, there are a couple of workarounds, like only deleting the keys your app uses, or configuring RevenueCat with a separate instance of NSUserDefaults. Let me know if this is your case and I can elaborate more.

[owenkealey]

I have no idea honestly, I just setup the purchases library as was instructed in the Flutter documentation for Revenue Cat.

…

On Thu, May 21, 2020 at 2:28 PM aboedo ***@***.***> wrote: Is your app deleting NSUserDefaults? If so, that would explain the crash. If that is the case, there are a couple of workarounds, like only deleting the keys your app uses, or configuring RevenueCat with a separate instance of NSUserDefaults. Let me know if this is your case and I can elaborate more. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#51 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AGH6KGFEBZCOOIEKA5C47ZTRSVXFXANCNFSM4NFN7CFQ> .

[aboedo]

I see. My thinking is that there might be a plugin or something (or the app itself) that's deleting user defaults.
I'm working on #49, which will allow for a quick workaround for this issue on flutter. I'll keep you posted.
In the meantime, are you using any plugins like shared_preferences that might be causing this?

[owenkealey]

I am using flutter_secure_storage

…

On Thu, May 21, 2020 at 3:28 PM aboedo ***@***.***> wrote: I see. My thinking is that there might be a plugin or something (or the app itself) that's deleting user defaults. I'm working on #49 <#49>, which will allow for a quick workaround for this issue on flutter. I'll keep you posted. In the meantime, are you using any plugins like shared_preferences <https://flutter.dev/docs/cookbook/persistence/key-value> that might be causing this? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#51 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AGH6KGEVXGVSRZEGQ4EVWLLRSV6G3ANCNFSM4NFN7CFQ> .

[aboedo]

thanks for the info. That one should be safe, since it internally uses the keychain for storage (from their docs).
I'm not sure what might be causing NSUserDefaults getting cleared in your case, but I'll let you know as soon as I get the workaround out.
in #49 there's another workaround that might help, although that one involves a bit more work on the dev side