FAQ & Troubleshooting
Building
F2613 Unit 'Skia.FMX' not found
Your code (or an element written for FMXER v.1.1) uses the unit names of the standalone Skia4Delphi. Since v.1.2 FMXER requires Delphi 12+ and its built-in Skia: use System.Skia, FMX.Skia and FMX.Skia.Canvas, see Installation.
F2613 Unit 'SubjectStand' (or 'FMX.IconFontsImageList', 'DelphiZXIngQRCode') not found
A dependency is not in the search path. Either initialize the submodules (git submodule update --init) and add their source folders, or install the libraries (GetIt, setup). See Search path.
The MyTicketing and EKON25 - Weather demos do not compile
They were written for FMXER 1.0 and use properties that became fluent setters in 1.1 (Title → SetTitle, Text → SetText, OnClickProc → SetOnClickHandler...). They are not part of AllDemos.groupproj; use them as reading material.
Runtime
Navigator has not been initialized
Something called Navigator before Navigator(FormStand1). Initialize it first thing in the main form's OnCreate (or constructor), before any route definition.
Route definition not found: xyz
RouteTo was called with a name that was never passed to DefineRoute. Route names are case-sensitive. Define every route before the first RouteTo — keeping the names in constants helps (the LibraryStore demo does).
EListError: Unbalanced stack or queue operation when closing (v.1.1)
CloseAllRoutes/CloseAllRoutesExcept closed a transient route as if it were on the stack. Fixed in v.1.2; on v.1.1 close transient routes with CloseRoute(AName, True) before closing the others. See Navigation.
The Back button closes the wrong screen, or nothing (v.1.1)
CloseRoute removed the top of the navigator's stack whatever route it closed. Fixed in v.1.2; on v.1.1 close routes in reverse order of opening.
Text is invisible
TTextFrame uses TAppColors.PrimaryTextColor (white by default), meant for text on the primary color. On a white background call SetFontColor(TAlphaColorRec.Black).
Icons are squares, or empty
The Material Design Icons Desktop font is not available. Install it on Windows, deploy it on the other platforms. See The icon font.
Access violation after closing a screen
A closure that references elements of the closed screen ran after the screen was freed: a message subscription, a timer, a background task, a callback. Unsubscribe or cancel it when the element is freed — see Subscriptions and the lifetime of elements.
EInvalidCast from SetPadding<T> on a form, or from AddActionButton(ACaption, AParams) (v.1.1)
Both fixed in v.1.2. On v.1.1 use the non-generic SetPadding(Value) on forms, and pass an OnClickProc param (or use AddActionButton(ACaption, AOnClickProc)).
The list shows every item twice after pull-to-refresh (v.1.1)
Fixed in v.1.2. On v.1.1 clear the items at the start of your ItemBuilderProc (List.ClearItems), or turn pull-to-refresh off with List.ListView.PullToRefresh := False.
A screen with many elements is slow to open
Each form element (TColumnForm, TRowForm, ...) creates a native window on Windows (about 2.5 ms), and adding elements one by one to a column costs O(N²). Use TColumnFrame/TRowFrame for columns and rows created many times, and BatchUpdate to add many elements; for hundreds of uniform rows use TListViewFrame. See Performance.
The elements of a row/column overlap or are cut
Every AddFrame gets the height (column) or width (row) you pass, 200 by default. Pass the size you want, or AUTO_HEIGHT/AUTO_WIDTH to use the element's own size, and put columns longer than the screen in a TVertScrollFrame. See Composing Layouts.
Design
Can I mix FMXER with classic forms?
Yes. An FMXER element is just a frame or a form, and any form can be a route (DefineRoute<TMyForm>); any frame can be put in an FMXER container (SetContentAsFrame<TMyFrame>). You can also use FMXER containers in a classic form: drop a TFormStand on it and call FormStand1.NewAndShow<TColumnForm>(Layout1, '', procedure (Col: TColumnForm) ...) to fill Layout1 with a column.
Can I see FMXER screens at design time?
No: they are built in code. Each element can be opened in the designer on its own, and the demos show complete screens.
How do I pass data to a route?
Routes have no parameters: set the value somewhere the route definition can read it (a data module, a field of the main form, a captured variable) and then RouteTo. The route's configuration procedure runs at that moment and reads the current value. See State & Events.
Is there an AI agent skill for FMXER?
Yes: the fmxer-development skill in the Skills/ folder of the repository, installable as a Claude Code plugin, with npx or by hand. See AI Agent Skill. The llms.txt and llms-full.txt files of this site give an AI assistant the whole documentation in one request.